Category: Frank ICSE

Frank ICSE Solutions for Class 9 Biology – The Skeletal System

PAGE NO:162

Solution 1:
Bones of skull, vertebral column, sternum and ribs.

Solution 2:
Longest bone – Femur
Smallest bone – Stapes of middle ear.

Solution 3:
There are seven cervical vertebrae. First vertebra is called atlas, second is axis while the rest are called typical cervical vertebrae.

Solution 4:
The skeletal system performs the following functions in an animal:

1.  It provides a framework to support the body and gives a definite shape and form to the body.
2.  It helps to protect some of the vital organs like heart, lungs, brain and spinal cord.
3. It provides the base for attachment of muscles and several bones so as to make body movements possible.
4. Bones act as storehouse of some minerals like calcium and phosphorus.
5. Red bone marrow of long bones of limbs produces red blood cells and granulated white blood cells in their hollow cavities.

Solution 5:

1. Axial skeleton
2.  Appendicular skeleton

Solution 6:
The various parts of a human skeleton are:

1. Axial skeleton: This consists of skull, vertebral column, sternum and ribs
2. Appendicular skeleton: It consists of pectoral and pelvic girdles and bones of limbs.

Solution 7:

Solution 8:
On the basis of position, endoskeleton is divided into two main parts:

 Axial skeleton: This consists of skull, vertebral column, sternum and ribs. Human skull has 22 bones of which 8 are present in the cranium and 14 on the face. Brain is present in the cavity called cranium. In the occipital region is an opening called foramen magnum through which spinal cord passes. Cranium has 8 bones which covers the brain from all sides.
 Facial bones: These bones form the face and protect the sensory organs present in the head. It has 14 bones.
Vertebral Column:
It makes the axis of the body and provides support like a pillar. Vertebral column is divided into following five parts:

1.  Cervical Region. It has 7 cervical vertebrae. First vertebra is called atlas, second is axis and rest are called typical cervical vertebrae.
2.  Thoracic Region. It has 12 thoracic vertebrae. Neural spine of these vertebrae is long and pointed, which provdes surface for muscle and attachment.
3. Lumber Region. It has 5 lumber vertebrae.
4.  Sacral Region. It has 5 sacral vertebrae which are permanently fused to each other. These are situated on both halves of pelvic and form a joint with pelvic girdle.
5.  Caudal Region. It has 4 caudal vertebrae. These are also fused to form a triangular structure which is called coccyx.

Sternum and Ribs
Sternum is the bone at the mid-ventral line of the thorax to which most of the ribs are attached at their ventral ends. Ribs are formed by vertebral and sterna part. First seven pairs of ribs are called true ribs. These are joined on one side with sternum and on second side with thorax.
Appendicular skeleton: It consists of limbs, shoulder or pectoral girdle and hip or pelvic girdles and bones of limbs.

1. Bones of the fore arm: Humerus, radius, Ulna, Carpals, Metacarpals, finger bones, etc.
2.  Bones of hind limb: Femur, Tibia, Fibula, Tarsal, Metatarsal, etc.
3.  Pectoral Girdle: In mammals, two halves of pectoral girdle are situated at equal distance from the ribs on the dorsal plane. Each of it is called shoulder bones. Each half of it made up of a triangular flat bone called scapula. From its outer side a projection arises called acromion and has a cavity called glenoid cavity.
4.  Pelvic Girdle: It consists of two similar halves. In each, three bones are found, ilium, ischium and pubis. Pubis bones of both halves are joined and are called pubic sysmphysis. Ilium and ischium form acetabulum cavity in which head of femur articulates by forming ball and socket joint. A hollow space is found between pubis and ischium, which is called obdurate foramen, which provides passage for obturatry artery, vein and nerve.

Solution 9:

Solution 10:

Solution 11:
Importance of pectoral girdle:

1. It provides support to the anterior portion of the body.
2.  Provides surface articulation of fore arms.
3.  Provides surface for muscle attachment.
4.  Provides protection to vital organs like heart and lungs.

Importance of pelvic girdle:

1. Provides surface articulation of hind limbs.
2. Provides surface for joining of muscles.
3.  Provides protection to the uterus.
4. Protects from shocks.

Solution 12:
The place of joining of two or more than two bones is called joint.

Solution 13:
Flexor is a muscle that causes bending of a limb or other part e.g. thigh muscle.
Extensor is the muscle that causes the straightening of a limb or other part. E.g. for extending the foot
Levator is the muscle that raises any part of the body.
Rotator is a muscle that rotates one part on another.

Solution 14:
Axial skeleton: This consists of skull, vertebral column, sternum and ribs. Human skull has 22 bones of which 8 are present in the cranium and 14 on the face. Brain is present in the cavity called cranium. In the occipital region is an opening called foramen magnum through which spinal cord passes. Cranium has 8 bones which covers the brain from all sides.
Facial bones: These bones form the face and protect the sensory organs present in the head. It has 14 bones.
Vertebral Column:
It makes the axis of the body and provides support like a pillar. Vertebral column is divided into following five parts:

1. Cervical Region. It has 7 cervical vertebrae. First vertebra is called atlas, second is axis and rest are called typical cervical vertebrae.
2. Thoracic Region. It has 12 thoracic vertebrae. Neural spine of these vertebrae is long and pointed, which provdes surface for muscle and attachment.
3. Lumber Region. It has 5 lumber vertebrae.
4.  Sacral Region. It has 5 sacral vertebrae which are permanently fused to each other. These are situated on both halves of pelvic and form a joint with pelvic girdle.
5. Caudal Region. It has 4 caudal vertebrae. These are also fused to form a triangular structure which is called coccyx.

 Sternum and Ribs:
Sternum is the bone at the mid-ventral line of the thorax to which most of the ribs are attached at their ventral ends. Ribs are formed by vertebral and sterna part. First seven pairs of ribs are called true ribs. These are joined on one side with sternum and on second side with thorax.
 Appendicular skeleton: It consists of limbs, shoulder or pectoral girdle and hip or pelvic girdles and bones of limbs.

1. Bones of the fore arm: Humerus, radius, Ulna, Carpals, Metacarpals, finger bones, etc.
2.  Bones of hind limb: Femur, Tibia, Fibula, Tarsal, Metatarsal, etc.
3. Pectoral Girdle: In mammals, two halves of pectoral girdle are situated at equal distance from the ribs on the dorsal plane. Each of it is called shoulder bones. Each half of it made up of a triangular flat bone called scapula. From its outer side a projection arises called acromion and has a cavity called glenoid cavity.
4. Pelvic Girdle: It consists of two similar halves. In each, three bones are found, ilium, ischium and pubis. Pubis bones of both halves are joined and are called pubic sysmphysis. Ilium and ischium form acetabulum cavity in which head of femur articulates by forming ball and socket joint. A hollow space is found between pubis and ischium, which is called obdurate foramen, which provides passage for obturatry artery, vein and nerve.

Solution 15:
Forelimbs consists of one humerus (anterior arm bone), one radius and one ulna (posterior arm bones), 8 carpals (wrist bones), 5 metacarpals ( palm bones) and 14 phalanges (finger bones).
Hindlimb consists of one femur bone or thigh bone, one tibia and fibula which are bones of the leg, 8 tarsals (bones of ankle), 5 metatarsals (bones of feet), and 14 phalanges (bones of fingers).

Solution 16:
The three levers found in the human skeleton are:

1. First order levers
2. Second order levers
3. Third order levers

Solution 17:

1. Ball and socket joint
2. Pivot joint

Solution 18:
In a ball and socket joint, the ball of one bone is fitted into the socket of another bone such that the ball can move in the socket. Such a joint always involves a long bone, which can move in all planes. This type of joint is found in pectoral girdle, glenoid cavity, femur and acetabulum of pelvic girdle.

Solution 19:
Forelimbs consists of one humerus (anterior arm bone), one radius and one ulna (posterior arm bones), 8 carpals (wrist bones), 5 metacarpals (palm bones) and 14 phalanges (finger bones).
Hind limb consists of one femur bone or thigh bone, one tibia and fibula which are bones of the leg, 8 tarsal (bones of ankle), 5 metatarsals (bones of feet), and 14 phalanges (bones of fingers).

Solution 20:
Biceps muscles first contract to bend the arm, following which the triceps muscles act to straighten the arm. Thus act in opposite ways and are antagonistic muscles, since they counteract each other’s action. The muscles of biceps are called flexor muscle while that of the triceps is the extensor muscle. This whole coordination of muscular action is under the nerve impulse and brain control.

Solution 21:
Muscles which counteract each other’s actions are known as antagonistic muscles. Biceps and triceps are two such muscles.

Solution 22:
Biceps cause bending of a limb or other part. Triceps cause straightening of a limb or other part.

Solution 23:
Striped, Unstriped and cardiac muscles.

Solution 24:

1.  Synovial joint is a movable joint present between the adjoining bones which can move independently. The articulating surfaces of the two bones are covered with articular cartilage. The joint is covered with a synovial membrane which secretes synovial fluid for lubrication.
2.  These are found in elbow joint, knee joint, femur and pelvic girdle, etc.
3. The cartilages cover the ends of the adjoining bones. They function to absorb shock and reduce friction during movement.
4. 1 and 5 -epiphyseal bone
   2- synovial cavity
   3- synovial fluid
   4- synovial membrane

Solution 25:

1. (a)  Scapula;
2. Shoulder joint;
3.  Humerus;
4. Bicep;
5. Tricep;
6. Radius;
7. Tricep
8. Elbow Joint;
9. Ulna.

(b) Bicep muscles and triceps are antagonistic muscles.
(c) Bicep muscles.
(d) Shoulder bones.
(e) Ball and socket joint.

PAGE NO:163

Solution 26:

1. (d) all the above
2. (c) 24
3. (b) 7
4. (a) Parietals of skull
5. (d) stapes
6. (b) Cranium
7. (c) It allows movement in all directions.

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Frank ICSE Solutions for Class 9 Biology – Digestive System

 

PAGE NO:151

Solution 1:
Nutrition can be defined as the process which involves the utilization of food by an animal to obtain energy for growth and development. There are two types of nutrition – autotrophic and heterotrophic.

Solution 2:

1.  Autotrophs: These are the organisms which prepare organic food in their body from simple inorganic materials like carbon dioxide, water, etc. Example – green plants and certain protests.
2. Heterotrophs: The organisms which cannot prepare their own food and depends on ready-made food synthesized by green plants are called heterotrophs. Examples – animals and human beings.
3. Carnivores: The organisms which feed upon other animals and animal products. Examples – tiger, lion, cat, etc.
4. Omnivores: The organisms which feed on all kinds of plant and animal food are called omnivores. Examples – Cockroach and human beings.
5. Herbivores: The organisms that feed on plants only are termed as herbivores. Examples – sheep, cow, goat, etc.

Solution 3:

1.  Parasites are the organisms that live in or on the body of another organism called host, and obtain nourishment from its body whereas saprophyte is an organism that absorbs soluble organic nutrients from dead and decaying organic matter.
2. Autotroph is an organism which prepares organic food in their body from simple inorganic materials like carbon dioxide, water, etc. whereas heterotroph is an organism which cannot prepare its own food and depends on ready-made food synthesized by green plants.
3. Holozoic nutrition is a nutrition in which animals survive by consuming other organisms whereas saprozoic nutrition is the nutrition in which the animals absorbs soluble organic nutrients from dead and decaying organic matter.
4.  Holophytic nutrition is the nutrition in which organisms prepare organic food in their body from simple inorganic materials like carbon dioxide, water, etc. whereas in holozoic nutrition, the animals survive by consuming other organisms.

Solution 4:
The steps involved in animal nutrition are:

1. Ingestion – It means taking solid or liquid food inside the body.
2. Digestion – It is the breaking down of complex insoluble food components into simple soluble substances.
3.  Absorption – It is the process by which soluble soluble digested food passes from alimentary canal into blood and lymph through intestinal villi.
4. Assimilation – Utilization of absorbed food by different body cells is called assimilation.
5.  Egestion – Elimination of undigested food as faeces is called egestion.

Solution 5:
There are four types of teeth:

1. Incisors – These are used for cutting.
2.  Canines – These teeth are used for tearing.
3.  Premolars – For masticating the food.
4. Molars – For grinding and masticating the food.

Solution 6:

Solution 7:

Solution 8:
(a) False
(b) False
(c) True
(d) False

Solution 9:

Solution 10:

Solution 11:

Solution 12:
Salivary Glands – Three pairs in man and secrete 1000 to 1500 cc saliva per day.
Saliva is slightly acidic and its pH is 6.8.
There are three types of salivary glands:

1.  Parotid glands: It is the largest salivary gland and situated near the ears. It opens into oral cavity by Stenoson’s duct.
2.  Sublingual glands: It is located beneath the tongue. It opens into the floor of oral cavity by duct of Rivinus.
3.  Submadibular or sub-maxillary glands: It is situated at the angles of the lower jaws. It opens inot oral cavity by Whartson’s duct.
   Each gland secret secretes saliva which is transported to the mouth cavity. At the time secrete saliva.

Solution 13:
(a) Lipase
(b) Lungs
(c) Rectum

Solution 14:

Solution 15:

Solution 16:

Solution 17:
(a) Carboxypeptidase
(b) Rennin
(c) Caecum
(d) HCl
(e) Pepsin
(f) Digestion
(g) Protein
(h) Bilirubin

Solution 18:

Solution 19:

1. Stomach – Pepsin
2. Salivary glands – Salivary amylase/Ptyalin
3. Pancreas – Trypsin, Chymotrypsin, Carboxy peptidase, Pancreatic amylase and Pancreatic lipase.
4.  Ileum – Enterokinase, Endokinase, Aminopeptidase and Dipeptidase.

Solution 20:

Frank ICSE Solutions for Class 9 Biology – Nutrition in Man

PAGE NO:138

Solution 1:
Carbohydrates provide energy and warmth to our body.

Solution 2:
Sources of Vitamin C are Lemon and carrot and sources of Vitamin A are Green vegetables and egg yolk.

Solution 3:
Vitamin C

Solution 4:
Pigs and crows

Solution 5:
Carbohydrates

Solution 6:
Roughage

Solution 7:
Assimilation

Solution 8:
Fats

Solution 9:

1. Carnivores are flesh-eating animals that eat other animals. Example – Snakes, Lion, tiger, vulture
2. Omnivores are animals that feed on both animals and plants. Example – crows, certain bears.
3.  Scavenger is any animal that feeds on refuse and other decaying organic matter. Example – vultures, dung beetle.

Solution 10:

Solution 11:
Food is a mixture of nutritive substances which when taken and incorporated into the body tissues provide materials for energy, repair, growth, reproduction, regulation of life processes and resistance to diseases.

Solution 12:
Proteins are used in the synthesis of new protoplasm to be utilized in growth and tissue repair. Hence they are called body building foods.

Solution 13:
(a) Night-blindness
(b) Protein
(c) Vitamin D
(d) Insectivore

Solution 14:
(a) False
(b) True
(c) True
(d) False
(e) True

PAGE NO:139

Solution 15:
Water is necessary for our body because:

1.  Water acts as solvent for many organic and inorganic compounds
2.  Water facilitates the movement of food materials, waste products and other chemical substances in the cytoplasm and circulatory process.
3.  It plays an important role in regulating body temperature and osmotic pressure of the body fluids.
4.  Water serves as good medium for various metabolic reactions.

Solution 16:
The undigested fibrous material present in the food is called roughage. Raw vegetables, and bran are examples of roughage

Solution 17:
(a) energy
(b) glycogen
(c) fatty acid, glycerol
(d) sucrose, maltose

Solution 18:

1. The condition where people become weak and sick due to insufficient and unbalanced diet is referred to as malnutrition.
2.  Saprozoic nutrition refers to nutrition in which animals feed on dead or decaying matter.
3. Vitamins are organic compounds regularly required in minute quantities in the diet for normal metabolism, health and growth.

Solution 19:
(a) Milk
(b) Sugarcane
(c) Plants
(d) Yellow and green vegetables

Solution 20:

1. Kwashiorkor develops in children whose diet is deficient in proteins even if sufficient carbohydrates and fats are consumed. This disease is common among infants and children up to 3 years old. The symptoms of Kwashiorkor include reduced body weight, slurred growth, protruding belly and thin legs.
2.  Marasmus is a form of prolonged protein energy malnutrition. It affects infants under one year of age. The symptoms of Marasmus include irreversible muscle degeneration, dry, wrinkled skin, prominent ribs and thin legs.

Solution 21:

1.  Deficiency of iron leads to anaemia.
2.  Deficiency of iodine leads to goitre.

Solution 22:

1. (a) 500 gm
2. (d) food
3. (b) rice
4. (b) Carrot
5. (a) A, D and E
6. (d) K
7. (c) Protein
8. (a) C

Frank ICSE Solutions for Class 9 Biology – Bacteria and Fungi Their Importance

PAGE NO:127

Solution 1:

1.  Bacteria are a large group of unicellular, prokaryotic microorganisms.
2.  The bacteria which do not get stained with crystal violet and iodine solution are called gram negative bacteria while those bacteria which get stained with crystal violet and iodine solution are called gram positive bacteria.

Solution 2:

1. Bacteria shows the presence of cell wall, hence they are included under plants.
2.  Spore formation helps bacteria to survive during adverse environmental conditions. Hence it is a survival technique.
3.  Bacteria as friends :
   Bacteria are useful to us in many ways like producing antibiotics, forming curd and cheese, tanning leather, producing various industrial products, nitrogen fixation, digesting cellulose etc.
   Bacteria as foes:
   They are harmful in many ways like causing diseases, bio-weapons , food spoilage etc.
4. Yeast is used in breweries since the fermentation activity of yeast produces different types of beverages like wine, beer, alcohol toddy etc. In bakeries, when yeast is added to the flour its fermentation results in the production of carbon dioxide which produces soft bread and other bakery products.

Solution 3:

Solution 4:

Solution 5:

PAGE NO:128

Solution 6:

Solution 7:
(a) Penicillium notatum
(b) Aspergillus fumigatus
(c) Candida albicans
(d) Aspergillus

Solution 8:
(a) chitin
(b) saprophytic
(c) obligate aerobes
(d) Agaricus campestris

Solution 9:

Solution 10:
Fungi are cooked like vegetables or used in pulao or prepared as soups. Some common edible fungi are Agaricus, Ramaria, Clavaria, Morchella.
Also yeast is used in preparing idli and dosa from a mixture of powdered rice and dal.

Solution 11:
Yes. Many types of antibiotics are obtained from fungi which are used in medical sciences. Today about 25 types of antibiotics are commercially produced from moulds.
For example: Penicillin is obtained from the fungus Penicillium notatum.
Griseofulvin is extracted from the fungus Penicillium griseofulvum.

Solution 12:

Solution 13:

1. (b) Leeuwenhoek
2. (a) bacteria
3. (b) Bacillus
4. (a) Tuberculosis
5. (d) Rhizobium
6. (b) Lactobacillus
7. (d) Agaricus
8.  (a) ethyl alcohol

BiologyChemistryPhysicsMaths

Frank ICSE Solutions for Class 9 Biology – Diversity of Life and Classification

PAGE NO:117

Solution 1:
Diversity refers to the variety of living organisms found within a given ecosystem, biome, or on an entire planet.

Solution 2:
The method of arranging organisms into series of groups on the basis of similarities and differences is called classification.
Classification is important in the following ways:

1.  It makes the study of a wide variety of organisms easy.
2.  It gives us an overall picture of all the life-forms.
3. It helps us to understand the interrelationships among different groups of organisms.
4. It forms a base for the development of other biological sciences.

Solution 3:

Solution 4:
Taxonomy is the study of the theory, practice and rules of classification of living and extinct organisms.

Solution 5:
The five kingdom system of classification was proposed by R. H. Whittaker in 1969. This classification is based on the following four facts:

• Complexity of cell structure
•  Methods of nutrition (autotrophic or heterotrophic)
• Complexity of body organization.
•  Phylogenetic relationships.

The five kingdoms in this system are:

1. Monera – It includes all the prokaryotes like bacteria and cyanobacteria. They are important decomposers.
2.  Protista – It includes the aquatic, eukaryotic, acellular organisms like protozoans.
3. Fungi – This kingdom includes moulds, mushrooms and yeasts.
4. Plantae – It includes all the coloured, multicellular, eukaryotes with cell walls.
5.  Animalia – These are multicellular eukaryotes lacking cell wall and showing heterotrophic nutrition.

Solution 6:
Important characters of five kingdom are:
 Characters of kingdom Monera are:

1. It contains acellular organisms, ranging in size between 0.15  to 2.0 .
2.  They are prokaryotes, lacking a well-defined nucleus .
3. They usually lack chlorophyll and hence are parasites or saprophytes.
4. Reproduction occurs by binary fission or budding in bacteria.
   Example – Actinomycetes, bacteria, cyanobacteria.

Characters of kingdom Protista are:

1.  They are aquatic, unicellular organisms.
2. They have eukaryotic cells with well-defined nucleus and organelles.
3. They show autotrophic or heterotrophic mode of nutrition.
4. Some protists are parasites and few are decomposers too.
   Example – Euglena, Ameoba, Paramoecium.

 Characters of kingdom Fungi:

1.  They may be unicellular or multicellular.
2. They have heterotrophic nutrition and mostly they are saprophytes.
3. Their body is made up of mycelium, a filament of which is called hypha.
4.  Their cell wall is made up of chitin.
   Example – Aspergillus, Agaricus, Penicillium.

 Characters of kingdom Plantae:

1. They are multicellular, eukaryotic organisms.
2.  The cell membrane is surrounded by a thick cell wall of cellulose.
3. Except a few aquatic life forms, plants are non-motile.
4.  They have different modes of nutrition: autotrophic, parasitic even
   insectivorous.
   Example – Mango, Cycas, Fern, Moss.

 Characters of kingdom Animalia:

1.  They are multicellular, eukaryotic organisms without cell wall.
2. They show heterotrophic mode of nutrition.
3. They can retract or expand with the help of muscles.
4.  They are consumers in-between producers and decomposers.
   Example – Fish, Frog, Earthworm, Man.

Solution 7:
The kingdom Plantae has been divided into following groups:
Thallophyta 

•  They are consists of red, green and brown algae.
•  Algae are of universal occurrence.
•  Their body ranges from unicellular to multicellular colonies, filaments or sheets of cells.
• Vascular tissues are absent.
•  Nutrition is generally autotrophic (through photosynthesis).
• Reproduction is vegetative or sexual.

 Bryophyta

•  It consists of liverworts and mosses.
• They are terrestrial, found in damp, shady places.
•  Their life cycle has a long gametophytic phase and a short sporophytic phase.
• Liverworts have prostrate thalloid gametophytic body, but mosses have erect body.
• True roots are absent, but rhizoids presents.
•  Vascular tissues are absent.
•  Nutrition is generally autotrophic (through photosynthesis).
•  Reproduction is vegetative or sexual.

 Pteridophyta 

• They include ferns, horse-tails and club mosses.
• They occur mainly in cool, shady and moist places.
• They are mostly terrestrial.
• They are perennial herbs with stem in the form of rhizome.
•  Fibrous roots present.
• Their life cycle has a gametophytic phase and a short sporophytic phase.
•  Vascular tissues are present.
•  Nutrition is generally autotrophic (through photosynthesis).
•  Reproduction is vegetative or sexual.

 Spermatophyta 

•  They are the most successful terrestrial plants having seeds.
•  They produce seeds (fertilized ovules).
• They are divided into two groups –

1.  Gymnosperms -They bear naked seeds and lack flowers.
   Examples: Pine, Cycas
2. Angiosperms – They produce seeds enclosed in ovary and flowers
   are present.
   Examples: Rose, Grass

Solution 8:

Solution 9:

Solution 10:
The various classes of Chordata are:

1. Pisces – Labeo (Rohu), Scoliodon (Dog fish)
2. Amphibia – Rana (Frog), Hyla (Tree frog )
3.  Reptilia – Kanchuga (Tortoise), Naja naja ( Cobra)
4.  Aves – Columba (Pigeon), Pavo (Peacock)
5. Mammalia – Elephas ( Elephant), Funambulas (Squirrel)

Solution 11:

Solution 12:
Characters of mammals are:

1. The females of this class are provided with mammary glands which produces milk to feed the young one.
2. Body usually covered with hair, spines, scales, nail, hoof or horn.
3.  External ear or pinna is well-developed.
4. They are warm-blooded.

PAGE NO:118

Solution 13:
(a) Starfish belongs to phylum Echinodermata.
Two characters of starfish are:

1. Spines found on the body which is covered by calcareous plates.
2.  Body is star shaped with five radiating areas called ambulacra with inter-ambulacra in between.

(b) Whale belongs to phylum Chordata.
Two characters of whale are:

1. They are warm blooded marine animals.
2. Heart is completely four-chambered.

(c) Jelly fish belongs to phylum Coelenterata.
Two characters of jelly fish are:

1.  Body diploblastic having outer epidermis and inner gastrodermis with gelatinous mesoglea.
2. Tentacles are present around the mouth.

(d) Cockroach belongs to phylum Arthropoda.
Two characters of cockroach are:

1.  They have jointed legs.
2. Their exoskeleton is made up of chitinous cuticle which is shed from time to time.

Solution 14:

Solution 15:
Bryophyta – Liverwort and Moss.
Pteridophyta – Fern and Horsetail.

Solution 16:
Antedon (Sea lily) and Asterias (Star fish ).

Solution 17:
Whale

Solution 18:
Cockroach, crab

Solution 19:
Frog

Solution 20:
Echidna

Solution 21:
Earthworm – Pheretima posthuma and
Roundworm – Ascaris

Solution 22:

Solution 23:
(a) Arthropoda
(b) Porifera
(c) Mollusca

Solution 24:
(a) Protozoa
(b) Mollusca
(c) Annelida

Solution 25:
(a) Asterias (Star fish ), Echinus (Sea-urchin)
(b) Scoliodon (Dog fish), Labeo (Rohu)
(c) Fasciola ( Liver fluke), Taenia solium (Tapeworm)
(d) Ascaris ( Roundworm), Wuchereria (Filarial worm )
(e) Pheretima (Earthworm), Hirudinaria ( Leech )
(f) Palemon (Prawn), Periplaneta (Cockroach)

Solution 26:
(a) Annelida
(b) Coelenterata
(c) Arthropoda
(d) Echinodermata

Solution 27:
(a) Flame cells
(b) Nemathelminthes
(c) Annelida
(d) Porifera
(e) Chordata

Solution 28:

1. (a) three pairs of legs are present.
2. (a) coelentrata
3. (c) octopus
4. (c) paramoecium
5. (c) hippocampus
6. (a) Scorpion
7. (b) for five kingdom classification
8.  (a) prokaryotic and multicellular eukaryotic cell
9.  (d) plant
10. (d) C. Linnaeus
11. (c) Carolus Linnaeus

BiologyChemistryPhysicsMaths

Frank ICSE Solutions for Class 9 Physics – Light

PAGE NO: 261
Solution 1:
Convex mirror has a wider field of view.

Solution 2:
Convex mirror always produces an erect image of the object.

Solution 3:
Convex mirror is used in vehicles to see the traffic on rear side.

Solution 4:
We will use convex mirror to see an enlarged image of our face.

Solution 5:
Image of object placed at a long distance in front of a convex mirror is formed at principal focus. Radius of curvature of convex mirror is 20 cm.
Focal length of convex mirror = radius of curvature/2.
Focal length of convex mirror = 20/2 = 10 cm.
So image will form at principal focus 10 cm away from pole.

Solution 6:
Concave mirror can produce real and diminished image of the object.

Solution 7:
The distance of the principal focus from the pole of the mirror is called the focal length of the mirror.

Solution 8:
The mirror having +20 cm as its focal length is a convex mirror because focal length is taken positive only in case of convex mirror.

Solution 9:
The focal length of plane mirror is infinity.

Solution 10:
The mirror having -15 cm as its focal length is a concave mirror because focal length is taken negative only in case of concave mirror.

Solution 11:
Principal axis is the straight line passing through the pole and the centre of curvature.

Solution 12:
Linear magnification is defined as the ratio of the height of the image to the height of the object. It is taken to be positive for an image to be virtual and erect and negative when image is real and inverted.
Magnification = height of image / height of object.

Solution 13:
Pole is the centre of the reflecting surface, in this case spherical mirror.

Solution 14:
Centre of curvature is the centre of the imaginary sphere to which the mirror belongs.

Solution 15:
Three characteristics of light are:-

• Light waves can travel through vacuum.
• Light waves are transverse waves.
• The velocity of light in vacuum is 3 x 10⁸ m/s.

Solution 16:
Three distinctions between light and sound waves are

• Light waves can travel through vacuum while sound waves cannot.
• Light waves are transverse waves while sound waves are longitudinal waves.
• The velocity of light in air is 3 x 10⁸ m/s while the speed of light in air is just about 330 m/s.

Solution 17:

• When position of object is at infinity, concave mirror forms a point and Real image at Focus point.
• When position of object is beyond C, concave mirror forms a Diminished, Real and inverted image between F and C.
• When position of object is at C, concave mirror forms a Magnified, Real and inverted image at C.

Solution 18:
Image formed by a convex mirror is always Diminished, Virtual and Erect.

Solution 19:
Concave mirrors are used in reflecting microscope, in shaving and make up glasses and in ophthalmoscope.

Solution 20:

• The distance from the pole in the direction of incident ray is taken positive.
• The distance from the pole in the direction opposite to the incident ray is taken negative.

Solution 21:
Mirror formula is the relation between the focal length f of the mirror, the distance u of the object from the pole of the mirror, and the distance v of the image from the pole.
Mirror formula is
1/v +1/u = 1/f.
Linear magnification is defined as the ratio of the height of the image to the height of the object. It is taken to be positive for an image to be virtual and erect and negative when image is real and inverted.
Magnification = height of image / height of object.

Solution 22:
Mirror formula is the relation between the focal length f of the mirror, the distance u of the object from the pole of the mirror, and the distance v of the image from the pole.
Mirror formula is
1/v +1/u = 1/f.
Size of body = 1.5 m.
Magnification of body = 1.5.
Magnification = height of image / height of object.
Height of image = magnification x height of object.
Height of image = 1.5 x 1.5= 2.25 m.

Solution 23:
Linear magnification is defined as the ratio of the height of the image to the height of the object. It is taken to be positive for an image to be virtual and erect and negative when image is real and inverted.
Magnification produced by concave mirror is:
Magnification = height of image / height of object.
It is a pure ratio and does not have any units.

Solution 24:

Solution 25:
A smooth and polished surface causes regular reflection while a rough and unpolished surface causes irregular reflection.

Solution 26:
When rays of light fall on a surface, they are turned back into the same medium in accordance with some definite laws. This process is known as reflection.
Reflection obeys following two laws

• The incident ray, the reflected ray, and the normal at the point of incidence, all lie in the same plane.
• The angle of incidence and the angle of reflection are always equal.

Solution 27:
You can distinguish between plane mirror, a concave mirror, and a convex mirror without touching them. When you look into these mirrors by bringing your face close to each mirror, they will produce an image of your face of different types.

• A plane mirror will produce an image of the same size as your face.
• A concave mirror will produce a magnified image of your face.
• A convex mirror will produce Diminished image of your face.

Solution 28:
You can distinguish between a concave mirror and a convex mirror without touching them. When you look into these mirrors by bringing your face close to each mirror, they will produce an image of your face of different types.

• A concave mirror will produce a magnified image of your face.
• A convex mirror will produce Diminished image of your face.

PAGE NO : 262
Solution 29:

Solution 30:
Uses of concave mirror:

• Concave mirrors are used in reflecting microscope
• Concave mirrors are used in shaving and make up glasses.
  Uses of convex mirror: Convex mirrors are used as a rear view mirror in automobiles as it provides a wider view of following traffic.

Solution 31:
We can see the reflection of our face on a polished table top because a regular reflection occurs in case of a polished surface while on a unpolished table top irregular reflection occurs which make image of our face unclear.

Solution 32:

• The angle of incidence is the angle made by the incident ray with the plane mirror. {FALSE}
  Correct statement is the angle of incidence is the angle made by the incident ray with the normal to the surface of plane mirror.
• If a ray of light incident on a plane mirror is such that it makes an angle of 30° with the normal, then the angle of reflection is 60°.{FALSE}
  Correct statement is if a ray of light incident on a plane mirror is such that it makes an angle of 30° with the normal, then the angle of reflection is 30°.
• If the incident ray makes an angle of X° with the normal, then the angle between the incident ray and reflected ray is 2X°. {TRUE}
• The image formed in a plane mirror is real, erect and same size as that of the object. {FALSE}
  Correct statement is the image formed in a plane mirror is virtual, erect and same size as that of the object.

Solution 33:

Solution 34:

Solution 35:
The image formed by a plane mirror is erect and virtual. It is a laterally inverted image. The image formed is of the same size as that of the object. Also, the image and the object are equidistant from the mirror.

Solution 36:

Solution 37:
Given, distance of boy from the mirror = 3 m

• Distance of image from mirror = distance of boy from the mirror = 3 m
  Distance between boy and his image = distance of boy from the mirror + distance of image from mirror = 3+3 = 6 m
• Now, distance of boy from the mirror = 4 m
  Distance of image from mirror = 4 m
  Distance between boy and his image = distance of boy from the mirror + distance of image from mirror = 4+4 = 8m.

Solution 38:
Periscope is used to see over the top of an obstacle. It is also used in submarines for observing for movement of ships. It can be used from the trenches for observing the movement on the surface of earth.

PAGE NO : 263
Solution 39:

Solution 40:

• Pole is the centre of the reflecting surface, in this case spherical mirror.
• Centre of curvature is the centre of the imaginary sphere to which the mirror belongs
• Principal focus of a spherical mirror is a point on the principal axis of the mirror, where all the rays travelling parallel to the principal axis and close to it after reflection from the mirror, converge to or appear to diverge from.
• Principal axis is the straight line passing through the pole and the centre of curvature.
• Focus of a concave mirror is a point on the principal axis of the mirror, where all the rays travelling parallel to the principal axis and close to it after reflection from the mirror converge to that point.
• Normal to the surface of a mirror at any point is the straight line at right angle to the tangent drawn at that point.

Solution 41:

Solution 42:

Solution 43:

Solution 44:

Solution 45:

Solution 46:

PAGE NO : 264
Solution 47:

Solution 48:

Solution 49:

Solution 50:

PhysicsChemistryBiologyMaths

Frank ICSE Solutions for Class 9 Physics – Light: Spherical Mirrors

PAGE NO: 258
Solution 1:
A spherical mirror is a part of a hollow glass sphere silvered on one side.

Solution 2:

Solution 3:
Focal length = 1/2 of radius of curvature
= 1/2 x 30 = 15cm.

Solution 4:
Focal point is the principal focus of the mirror where a parallel beam of light meets(or appear to meet) after reflection from the mirror.

Solution 5:

Solution 6:

• Pole is the centre of the reflecting surface, in this case spherical mirror.
• Centre of curvature is the centre of the imaginary sphere to which the mirror belongs
• Aperture is the distance between the extreme points on the periphery of the mirror.
• Principal axis is the straight line passing through the pole and the centre of curvature.
• The principle focus of a spherical mirror may be defined as a point on its principle axis where a beam of light parallel to the principle axis converges to or appears to diverge from after reflection from the spherical mirror.

Solution 7:
Convex mirror has a wider field of view.

Solution 8:
Concave mirrors are used in reflecting microscope, in shaving and make up glasses and in ophthalmoscope.

Solution 9:
Convex mirrors are used as a rear view mirror in automobiles as it provides a wider view of following traffic.

Solution 10:
Convex mirror is used in vehicles to see the traffic following it.

Solution 11:
The relationship between the focal length, f and radius of curvature, r is
f = 1/2 x r.

Solution 12:

Solution 13:

Solution 14:
Concave mirror can produce real and diminished image of the object.

Solution 15:
The focal length of plane mirror is infinity.

Solution 16:
The object should be placed between F and P to obtain its magnified and erect image.

Solution 17:

Solution 18:
Linear magnification is defined as the ratio of the height of the image to the height of the object. It is taken to be positive for an image to be virtual and erect and negative when image is real and inverted.
Magnification = height of image / height of object.

Solution 19:
SI unit of focal length is meter.

Solution 20:
The top mirror is convex mirror, the middle mirror is concave mirror and bottom mirror is a plane mirror.

Solution 21:
The mirror having +15 cm as its focal length is a convex mirror because focal length is taken positive only in case of convex mirror.

Solution 22:
The mirror having -20 cm as its focal length is a concave mirror because focal length is taken negative only in case of concave mirror.

Solution 23:
When we look into a plane mirror, the image of our face is virtual because the image cannot be obtained on a screen.

Solution 24:
When an object is brought towards the concave mirror, the position of the image moves away from the mirror and the size increases and it remains inverted but at object position between F and P, the image is virtual, magnified and erect.

Solution 25:

PAGE NO : 259
Solution 26:

Solution 27:

Solution 28:

Solution 29:

Solution 30:

PhysicsChemistryBiologyMaths

Frank ICSE Solutions for Class 9 Physics – Light: Reflection of Light

PAGE NO: 245
Solution 1:
Light may be defined as the radiant energy which produces in us the sensation of sight. Light itself is invisible but makes other objects visible.

Solution 2:
Yes, light is a form of energy that produces the sensation of vision in our eyes.

Solution 3:
The velocity of light in vacuum is 3 x 10⁸ m/s.

Solution 4:
Two sources of light are

• Natural, for e.g. Sun
• Artificial, for e.g. Light bulb.

Solution 5:
Four characteristics of light are :-

• Light waves can travel through vacuum
• Light waves are transverse waves
• Wavelength of light waves is short so that their length is measured in centi-microns.
• The velocity of light in vacuum is 3 x 10⁸ m/s.

Solution 6:
The Sun and the stars are the two luminous bodies.

Solution 7:
Two non -luminous bodies are moon, chair.

Solution 8:

Solution 9:
A ray of light is the path along which light travels.

Solution 10:
Three distinctions between light and sound waves are

• Light waves can travel through vacuum while sound waves cannot.
• Light waves are transverse waves while sound waves are longitudinal waves.
• The velocity of light in air is 3 x 10⁸ m/s while the speed of light in air is just about 330 m/s.

PAGE NO : 246
Solution 11:

• A ray of light
• Divergent beam of light
• Divergent beam of light
• Parallel beam of light

Solution 12:
The substance through which light is made to pass is called medium.

Solution 13:
Rectilinear propagation of light is that the light travels along a straight line.

Solution 14:
No, glass is a transparent medium.

Solution 15:
No, no metal is transparent by nature.

Solution 16:

Solution 17:
Waxed paper is the translucent medium among the given substances.

Solution 18:

Solution 19:
Two observations that proves that light travels in a straight line are :-

• Sunlight coming through a hole in a dark room, we can easily see that light travels in a straight line
• Light coming from a laser light, used for presentation, can also be seen to travel in straight line.

Solution 20:
When rays of light fall on a surface, they are turned back into the same medium in accordance with some definite laws. This process is known as reflection.

Solution 21:
A smooth and polished flat surface is the cause of regular surface.

Solution 22:
Reflection obeys following two laws

• The incident ray, the reflected ray, and the normal at the point of incidence, all lie in the same plane.
• The angle of incidence and the angle of reflection are always equal.

Solution 23:
The height of plane mirror should be half of the size of the object to get a full image of the object. So for a man of height 1.6 m tall should use a 0.8m tall plane mirror.

Solution 24:
Rectilinear propagation of light is that the light travels along a straight line.

Solution 25:
Lateral inversion is the reversal of image experienced in a plane mirror. The image is of the same size and equidistant from the object but the left and right sides are transposed.

Solution 26:
Formation of image is the phenomenon based on laws of reflection.

Solution 27:
The principle employed in a periscope is successive reflections from two plane mirrors.

Solution 28:
The point at which the light is incident on the reflecting surface is called the point of incidence.

Solution 29:
Any smooth, highly polished reflecting surface is called mirror.

Solution 30:
A smooth, highly polished plane surface is called plane mirror.

Solution 31:
The angle between the incident ray and the normal to the surface at the point of incidence is called the angle of incidence.

Solution 32:

Solution 33:
Given, angle between incident ray and mirror = 35°

• Angle of incidence = angle of mirror to the normal – angle between incident ray and mirror
  = 90 – 35 = 55°
• Angle of reflection = angle of incidence = 55°
• Total angle turned = angle of incidence + angle of reflection
  = 55 + 55 = 110°
• The angle between incident ray and reflected ray = Angle of incidence + Angle of reflection
  = 55 + 55 = 110°

Solution 34:
Given, distance of boy from the mirror = 3 m

• Distance of image from mirror = distance of boy from the mirror = 3 m
  Distance between boy and his image = distance of boy from the mirror + distance of image from mirror = 3+3 = 6 m
• Now, distance of boy from the mirror = 4 m
  Distance of image from mirror = 4 m
  Distance between boy and his image = distance of boy from the mirror + distance of image from mirror = 4+4 = 8 m.

Solution 35:

PAGE NO : 247
Solution 36:
Two characteristics of image formed by plane mirror are

• Image is erect and virtual
• Image and object are of same size.

Solution 37:

Solution 38:

Solution 39:

PhysicsChemistryBiologyMaths

Frank ICSE Solutions for Class 9 Physics – Heat: Transmission of Heat

PAGE NO: 226
Solution 1:
Conduction, convection and radiation are three modes of transfer of heat.

Solution 2:
The process of conduction involves the transmission of heat from the hot end to the cold end from particle to particle of the medium.

Solution 3:
No, conduction is not possible in vacuum.

Solution 4:
Thermal insulation means restriction of transfer of heat by any means.

Solution 5:
Good conductor allow heat to pass through them easily while bad conductor of heat does not allow heat to pass them.

Solution 6:
No, liquids are poor conductors of heat.

Solution 7:

• Metals are the best conductor of heat.
• Gases are the worst conductor of heat.

Solution 8:
Among all the metals, Silver is most conducting.

Solution 9:
Air is most non-conducting.

Solution 10:
No, air is not a good conductor of heat.

Solution 11:
Yes, this is a correct statement. Ebonite and asbestos are worst conductor of heat.

Solution 12:
Cooking utensils are made up of metals because metals are good conductors of heat and they easily allow the heat to pass through them.

Solution 13:
Brick is bad conductor of heat, hence bricks greatly reduce the conduction of heat from outside to the room. In order to ensure better insulation, bricks are made hollow so that air filled between these gaps provides insulation to heat.

Solution 14:
Mercury is good conductor of heat.

Solution 15:
In cold countries, windows have two glass panes and a thin layer of air in between these two glass panes because air is a poor conductor of heat; it obstructs the conduction of heat from the room to the outside.

Solution 16:
Order of increasing heat conductivity:
Air < water< mercury < copper.

Solution 17:

• Water is heated from below because water is heated by process of convection and in process of convection heat always flows in upward direction from downward direction.
• In process of convection heat is transferred from one point to another by actual movement of particles of medium and as particles of solid cannot move so process of convection is not possible in case of solids.
• Conduction is not possible in Vacuum because process of conduction require a material medium for transfer of heat.
• Inside the refrigerator, cooling takes place by convection. The freezing chamber at the top produces cool and heavy air which descends and hot air from below goes up setting convection current. Thus, cooling in a refrigerator is kept near the top.
• As earth surface gets heated by sun rays and due to process of convection the air near earth surface open to sunlight get heated while in shade sun rays does not fall on earth surface so air near that surface would not heat up.

Solution 18:

Solution 19:

PAGE NO : 227
Solution 20:
We receive heat from sun by process of Radiation.

Solution 21:
Radiating power of a surface can be increased by blackening it.

Solution 22:
Heat radiation travels with speed of light and always follows straight path.

Solution 23:
The flask consists of a double walled glass container with vacuum between the walls A and B. The inner side of A and the outer side of B are silvered. It has a narrow mouth which is closed by a non-conducting rubber stopper.
If a hot liquid is placed inside the flask, it cannot lose heat by conduction or convection, as there is no air between the walls. The small amount of heat lost from the liquid by radiation is reflected back into the liquid by silvering of the inner wall A and any radiation striking the outer wall B, is reflected back and prevented from reaching the liquid.

Solution 24:
Green house is a glass house constructed to keep delicate and rare plants that require warmth and protection from weather. It is constructed by panels of glass. The temperature in a green house rises because heat enters the house through the glass but cannot escape out, because the glass reflects the heat back to the inside of the house. This makes glass house warmer than the outside environment.

Solution 25:
Take two sheets of tin plates, one blackened and the other is polished brightly. Fix some drawing pins on the outer side of both sheets using wax. Fix these plates vertically at a very short distance apart. Place a Bunsen burner midway between them. When you light the burner you will observe that the pins from the black painted sheet start dropping while the pins on the polished surface remain in the same position for much longer time.
Thus, we can conclude that black surface is better absorber of heat than the polished one.

Solution 26:

• As convection require medium for transfer of heat so heat loss due to convection can be minimized if the substance is kept away from any material medium.
• Similarly for conduction, as conduction also require medium for transfer of heat so heat loss due to conduction can be minimized if the substance is kept away from any material medium.
• Heat loss due to radiation can be minimized by polishing the surface as polished surfaces radiate less heat.

Solution 27:

• As no material medium surrounds the ball so there is no possibility of losing heat by conduction or convection. The ball will lose heat by Radiation.
• Ball will lose minimum amount of heat if it is polished.
• As loss of heat take place by Radiation and process of radiation does not require any material medium, so there is no role of air in loss of heat.

Solution 28:

• CFC means Chlorofluorocarbons which are produced mainly by refrigeration industries, aerosol cans, coolants, propellants and plastic foams. They cause global warming.
• UV means ultraviolet range of radiations. These are the radiations which are emitted by sun and they enter our atmosphere.
• WHO is World Health Organization which put a check on diseases and global warming etc.

Solution 29:
Green house is a glass house constructed to keep delicate and rare plants that require warmth and protection from weather. It is constructed by panels of glass. The temperature in a green house rises because heat enters the house through the glass but cannot escape out, because the glass reflects the heat back to the inside of the house. This makes glass house warmer than the outside environment. This phenomenon is called green house effect.

Solution 30:
Carbon dioxide, Carbon monoxide, methane are green house gases.

Solution 31:
As fossil fuels are non-renewable sources of energy they are not available again and again if are fully exhausted, so they should not be used extensively.

Solution 32:
Global warming occurs due to the presence of carbon di- oxide, CFCs, methane in the atmosphere. Carbon dioxide acts as a transparent gas to incoming shortwave radiations which the earth re-radiates into space. It therefore traps the outgoing longwave radiations thus warming lower atmosphere of the earth thereby causing global warming.

Solution 33:
Harmful effects of global warming are:

• The atmospheric temperature of earth would increase thereby making it difficult for a living being to survive.
• It would melt down the polar caps thus increasing the size of the ocean and leading to floods, tsunami, etc.
• The increase in temperature would affect climate and rainfall thus affecting flora and fauna.
• Human beings would be vulnerable to diseases as microbes would get warmth to grow.

PhysicsChemistryBiologyMaths

Frank ICSE Solutions for Class 9 Physics – Heat: Thermometry

PAGE NO: 209
Solution 1:
Temperature is the quantity that tells about the thermal state of a body i.e. the degree of hotness or coldness of a body.

Solution 2:
Thermometer is used for measuring the temperature of a body.

Solution 3:
Thermometer works on the principal that substances expand when heated and contract on cooling.

Solution 4:
Range of thermometer is the range of temperature which can be measured by thermometer.

Solution 5:
Mercury is the liquid used in a clinical thermometer

Solution 6:
The usual range of temperature marked on clinical thermometer is 95° F to 110°F.

Solution 7:
Fahrenheit designed the first thermometer.

Solution 8:
Before constructing a thermometer, we determine lower fixed point and upper fixed point and divide the whole range of thermometer into specific number of equal divisions to provide a scale for measuring the temperatures within a range.

Solution 9:
The clinical thermometer is specially designed thermometer used to measure the temperature of a human body easily and as accurately as possible.

Solution 10:
Three properties of a liquid which make it suitable to be used in a thermometer are:

• The substance should have high coefficient of expansion so that it is sensitive to the smallest change in temperature
• The substance should have uniform expansion all over its entire volume
• The substance should have minimum specific heat so that it absorbs minimum heat from the body under measurement.

Solution 11:
Two disadvantages of using mercury as a thermometric liquid:

• It does not have uniform expansion.
• Mercury is less sensitive than alcohol as its coefficient of expansion is less than alcohol.

Solution 12:
Three advantages of using mercury as a thermometric liquid:

• Mercury is good conductors of heat.
• Mercury have high coefficient of expansion thus is sensitive to the smallest change in temperature.
• Freezing points is very low and boiling point is high.

Solution 13:
Water is not used as a thermometric liquid because it has low coefficient of expansion so it is less sensitive to temperature changes. Moreover, it is transparent thus making it difficult to read the thermometer and water evaporates with time thus producing error and also the freezing and boiling points are also low.

Solution 14:
Temperature in Kelvin To K = Temperature in Celsius To C + 273.
To K = 0°C + 273
To K =273 K.

Solution 15:
Body temperature of a healthy person is 98.4oF.
We know C/100 = (F – 32)/180.
C =5/9(F- 32)
C = 5/9(98.4 – 32)
C = 5/9 x 66.4
C =36.88°C
Temperature of body of healthy man is 36.88°C.

Solution 16:
Absolute scale of temperature is Kelvin scale.
Conversion of temperature from Celsius to Kelvin scale is
Temperature in Kelvin To K = Temperature in Celsius To C + 273.
So a rise of temperature of 1°C in Celsius scale is equal to rise of 1°K in Kelvin scale.

Solution 17:
Kelvin temperature scale is used in SI system.

Solution 18:
In Celsius scale there are two fixed points namely lower fixed point and upper fixed point at 0°C and 100°C respectively. This range is divided into 100 equal divisions and each part gives 1°C.

Solution 19:
We know C/100 = (F – 32)/180.
C =5/9(F- 32)
9/5 C + 32 =F
F = 9/5 C + 32.
Temperature given in Celsius = -15°C.
F = 9/5 x (-15) +32
F = -27 +32
F = 5°F.

Solution 20:
Absolute zero of temperature is 0°K.
Temperature in Kelvin To K = Temperature in Celsius To C + 273.
0°K = To C +273.
To C = -273°C.
Absolute zero of temperature on Celsius scale is -273°C.

Solution 21:
Difference of temperature of two bodies in Celsius scale = 1°C.
We know C/100 = (F – 32)/180.
C =5/9(F- 32)
9/5 C + 32 =F
F = 9/5 C + 32.
So, difference of 1° in Celsius scale is equal to the difference of 9/5° in Fahrenheit scale.
Thus, Difference of 1°C of temperature of two bodies in Celsius scale is equal to difference of 1.8° in Fahrenheit scale.

Solution 22:
Celsius invented the Celsius scale of temperature.

Solution 23:
Fahrenheit invented the Fahrenheit scale of temperature.

Solution 24:
Mercury, alcohol are commonly used in thermometers.

PAGE NO : 210
Solution 25:
Camel and are two animals which are able to increase their body temperature in summers and decrease their body temperature in winters.

Solution 26:
CGS unit of heat is Joule denoted by J.
1 J is amount of heat required to raise the temperature of a body by 1/4.12°C of temperature.

Solution 27:

Solution 28:

Solution 29:
Relation between Celsius and Fahrenheit scales of temperature is
C/100 = (F – 32)/180.

Solution 30:
Temperature of ice point on Fahrenheit scale =32°F.
Temperature of steam point on Fahrenheit scale =212°

PhysicsChemistryBiologyMaths

Frank ICSE Solutions for Class 9 Physics – Heat: Thermal Expansion

PAGE NO: 202
Solution 1:

• Coefficient of Linear expansion is equal to the change in length of a rod of length 1m when its temperature rises by 1°c.
• Coefficient of superficial expansion is equal to the change in area of a rod of area 1m² when its temperature rises by 1°c.
• Coefficient of volume expansion is equal to the change in volume of a rod of volume 1m³ when its temperature rises by 1°c.

Solution 2:

Solution 3:
A bimetallic strip consists of two metal strips- one with high coefficient of expansion and the other with low coefficient of expansion. Two different metals are used for regulating temperature in an electrical device as the strip bends due to different coefficient of expansion on excessive heating due to current, thus breaking electrical circuit until the strip cools down to a preset point. Two applications of bimetallic strip are thermostat in electric iron and in balance wheels.

• When boiling water is poured into a glass bottle, it generally cracks because on pouring hot water in the bottle the inner surface heats up and expands more as compared to its outer surface. This unequal expansion between the two surfaces causes a strain and the bottle cracks.
• Telephone wires sag in summer because due to heat of the sun, the wire expands and increases in length, thus they sag in summer.
• In cold countries water pipes burst in winter because the water has maximum density at 4°C and, due to anomalous expansion of water, it expands when the water is cooled to a temperature below 4°C
• Even when the water in the lakes is frozen, fishes can survive due to anomalous expansion of water, water has maximum density at 4°C and this dense water remains at the bottom of the lake and the upper layer of water is less dense and freezes but the temperature of each layer of water below increases by 1°C. Thus it is warmer in the lakes below the ice layer. This helps the fishes to survive.

Solution 4:

Solution 5:
Thermostat is a device for regulating temperature in electric circuits and it is made up of bimetallic strip. Two applications of thermostat are in electric iron and in refrigerators.

Solution 6:
When heated, water expands normally but behavior of water is unusual over a small range of temperature between 0 and 4°C. This is known as anomalous expansion of water.

Solution 7:
Anomalous expansion of water slows down the complete freezing of water in the lake.

Solution 8:

Solution 9:

• When boiling water is poured into a glass bottle, it generally cracks because on pouring hot water in the bottle the inner surface heats up and expands more as compared to its outer surface. This unequal expansion between the two surfaces causes a strain and the bottle cracks.
• Telephone wires sag in summer because due to heat of the sun, the wire expands and increases in length, thus they sag in summer.
• In cold countries water pipes burst in winter because the water has maximum density at 4°C and, due to anomalous expansion of water, it expands when the water is cooled to a temperature below 4°C
• Even when the water in the lakes is frozen, fishes can survive due to anomalous expansion of water, water has maximum density at 4
• When boiling water is poured into a glass bottle, it generally cracks because on pouring hot water in the bottle the inner surface heats up and expands more as compared to its outer surface. This unequal expansion between the two surfaces causes a strain and the bottle cracks.
• Telephone wires sag in summer because due to heat of the sun, the wire expands and increases in length, thus they sag in summer.
• In cold countries water pipes burst in winter because the water has maximum density at 4°C and, due to anomalous expansion of water, it expands when the water is cooled to a temperature below 4°C.
• Even when the water in the lakes is frozen, fishes can survive due to anomalous expansion of water, water has maximum density at 4°C and this dense water remains at the bottom of the lake and the upper layer of water is less dense and freezes but the temperature of each layer of water below increases by 1°C. Thus it is warmer in the lakes below the ice layer. This helps the fishes to survive °C and this dense water remains at the bottom of the lake and the upper layer of water is less dense and freezes but the temperature of each layer of water below increases by 1°C. Thus it is warmer in the lakes below the ice layer. This helps the fishes to survive.

Solution 10:

Solution 11:

PAGE NO : 203
Solution 12:

• Maximum
• Increases; decreases
• Coefficient; expansion
• Anomalous expansion of water
• Calorie
• Kelvin(K)

Solution 13:
We should heat the neck of the bottle because due to heating the neck will expand and loosen the stopper stuck in the neck. In this way, we can easily remove the stopper.

Solution 14:
When a liquid is heated in a flask. Due to heat, the flask expands along with the liquid, thus providing more space for the liquid. Hence the level of the liquid falls. Thus this dropped level shows the apparent expansion of the liquid. The actual expansion of the liquid, when heated, is the real expansion.

Solution 15:
No, the both liquids i.e. mercury and alcohol will not have same volume on heating as they have different coefficient of expansions, thus they expand differently on heating at same temperature range. Alcohol expands more than mercury.

Solution 16:

Solution 17:

Solution 18:
A hot glass chimney often crack when a drop of water falls on it because the glass of the chimney expands due to constant heating by the flame of the chimney but as a cooler water drop falls on the glass, the outer surface contracts more than the inner side of the glass. . This unequal contraction between the two surfaces causes a strain and the glass cracks.

Solution 19:
No, we cannot fuse iron wire in glass rod because glass is bad conductor of heat and it does not allow heat to pass through it and iron wire would not be able to get sufficient heat to fuse.

Solution 20:
We should heat the neck of the bottle because due to heating the neck will expand and loosen the stopper stuck in the neck. In this way, we can easily remove the stopper from the bottle.

Solution 21:
Two substances that expand on heating are water and iron.

Solution 22:
Two substances that contract on heating are plastic and poly-ethene.

Solution 23:

Solution 24:
The joints in metal pipes loosen in summers because the joints get more space to expand due to the heat in summers as compared to the pipes therefore the joints become loose in summers

Solution 25:
The increase in length of a rod depends on the following factors

• material of the rod
• Original length of the rod
• Rise in temperature

Solution 26:
The given statement states that the change in length of the metal will be 0.000016 m when its temperature changes by 1°C.

Solution 27:
On heating the copper washer

• Its internal diameter will increase as the copper washer expands outwards
• Volume will increase as the size of the metal expands on heating
• Mass will remain the same as the mass does not change with change in temperature
• Density will decrease as the volume of the washer increases on heating and density is inversely proportional to volume
• External diameter will increase because the copper washer expands outwards

Solution 28:

Solution 29:
At 4°C, water has the maximum density due to anomalous expansion.

Solution 30:

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Frank ICSE Solutions for Class 9 Physics – Heat

PAGE NO: 191
Solution 1:
Heat is defined as a form of energy which flows from one point to another on account of temperature difference.

Solution 2:
Yes, heat is a form of energy

Solution 3:
Joule is the SI unit of heat.

Solution 4:
One calorie is defined as the quantity of heat required to raise the temperature of 1 gram of water through 1°C.

Solution 5:
1 calorie = 4.2 joules.

Solution 6:
Temperature is the degree of hotness or coldness of a body compared to other bodies around it.
SI unit of temperature is Kelvin (K).

Solution 7:
We feel cold on touching ice because heat flows from our warm hands to cold ice. Due to this flow of heat from hand to ice, the temperature of our hand falls. This is why we feel cold.

Solution 8:

Solution 9:
Heat flows from a body at a higher temperature to a body of lower temperature.

Solution 10:
Yes, heat is the cause of temperature because temperature of a body rises when the heat flows into the body.

Solution 11:
Heat changes the temperature of a body due to flow of heat in or out of the given body.

Solution 12:
Calorie. Because 1 calorie = 4.2 joules.

Solution 13:
No, the exact relation is as given
1 calorie = 4.2 joules.

Solution 14:
Yes, because the heat flow is only due to temperature difference between the temperature of two bodies.

PAGE NO: 229
Solution 1:
Temperature is the degree of hotness or coldness of a body compared to other bodies around it.
SI unit of temperature is Kelvin (K)

Solution 2:
Normal temperature of human body is 37°C.

Solution 3:
To convert 20°c into °F
T°C /100 = (T°f -32)/180
20/100 = (T°f – 32)/180
20 x 180/100 = T°f -32
T°f = 36+32 = 68°F

Solution 4:
Upper fixed point on the Celsius scale is 100°C.

Solution 5:
T_k = 80 K
T_c = T_k -273
T_c = 80 – 273
T_c = -153°C

Solution 6:
SI unit of latent heat is Joule per kg (J/kg).

Solution 7:
Relative humidity is defined as the amount of water vapour in the air compared to the amount needed for saturation.

Solution 8:
Coefficient of Linear expansion is equal to the change in length of a rod of length 1m when its temperature rises by 1°C. Its SI unit is °C^-1.

Solution 9:
Celsius was the scientist who discovered the first thermometer in 1710.

Solution 10:
According to principle of calorimetry of mixtures,
Heat gained = Heat lost

Solution 11:
SI unit of coefficient of cubical expansion is °C^-1.

Solution 12:
Two uses of bimetallic strip are

• As thermostat in electric iron
• As balance wheel in watches

Solution 13:
Telephone wires sag in summer because due to heat of the sun, the wire expands and increases in length, thus they sag in summer.

Solution 14:

Solution 15:
Not all substances expand on heating. Some examples of substances which do not expand on heating are plastics, polythene and rubber.

Solution 16:
Evaporation is the phenomenon of a change of a liquid into vapour without raising the temperature. Evaporation needs energy for phase change from liquid to gases. As water evaporates off your skin, it absorbs energy(heat) from the body to make the phase change to gas thus cooling the body.

Solution 17:
Factors affecting evaporation are

• Humidity- more the humidity less is the evaporation
• surface area- more the surface area more is the evaporation
• wind- more the wind more is the evaporation
• temperature- more the temperature more is the evaporation

Solution 18:
The cold air that blows from land towards sea during night, is called land breeze
The cold air that blows from the sea towards the land during the day is known as the sea breeze. These breezes are the examples of natural convection current.

Solution 19:
No, the conduction is not possible in gases. Gases are bad conductors.

Solution 20:
No, conduction is not possible in vacuum.

Solution 21:
The velocity of thermal radiations is equal to the speed of light i.e. 3 x 10⁸ m/s.

PAGE NO : 230
Solution 22:
We wear woolen clothes in winter because woolen clothes have tiny pores and air is trapped in these pores and being a bad conductor, the trapped air obstructs the flow of body heat to the surroundings.

Solution 23:
A newly made quilt is warmer than an old one because the cotton in the old quilt gets compressed and very little air will remain trapped in it, hence heat insulation is quite poor.

Solution 24:
In cold countries, water pipes are covered with poor conductors because poor conductor prevents water from freezing and thus prevent these pipes from bursting.

Solution 25:
Three devices used to detect heat radiations are

• Blackened bulb thermometer
• Differential air thermo scope
• Thermopile

Solution 26:
The increase in size of a body on heating is called thermal expansion.

Solution 27:
Linear expansion is the increase in length of a solid on heating.

Solution 28:
Coefficient of Linear expansion is equal to the change in length of a rod of length 1m when its temperature rises by 1°C.

Solution 29:
A bimetallic strip consists of two metal strips- one with high coefficient of expansion and the other with low coefficient of expansion.

Solution 30:
SI unit of coefficient of linear expansion is °C^-1.

Solution 31:
Water is the substance which contracts, when heated from 0°C to 4°C.

Solution 32:
Coefficient of volume expansion is equal to the change in volume of a rod of volume 1m³ when its temperature rises by 1°C.

Solution 33:
SI unit of coefficient of volume expansion is °C^-1.

Solution 34:
Two uses of bimetallic strip are

• As thermostat in electric iron
• As balance wheel in watches

Solution 35:
We should heat the neck of the bottle because due to heating the neck will expand and loosen the stopper stuck in the neck. In this way, we can easily remove the stopper from the bottle.

Solution 36:
When hot water is poured into a thick glass tumbler, it generally cracks because on pouring hot water in the tumbler the inner surface heats up and expands more as compared to its outer surface. This unequal expansion between the two surfaces causes a strain and the tumbler cracks.

Solution 37:
A substance is made up of molecules arranged in a lattice. On heating, the molecules vibrate faster in the lattice and bump into each other harder. So the distance between the molecules increases thus expanding lattice. Thus, the substances expand on heating.

Solution 38:
There are three types of thermal expansion

• Linear expansion
• Superficial expansion
• Cubical expansion

Solution 39:
Gaps are left in the railway tracks because the tracks gets heated during the day and as a result they increase in length. If the gaps are not provided, the railway line would buckle outward and may cause derailment.

Solution 40:
The beams of the bridges expand maximum during the summer days and contract maximum during the winter nights. If the beams are fixed at both ends on the pillars, they may develop crack due to expansion and contraction. To avoid this, beams are made to rest on rollers on the pillars to provide space for expansion.

Solution 41:

Solution 42:

Solution 43:

Solution 44:
A ventilator is provided in a room because it helps in removing the hot air from the room and allows the fresh and cold air to come in.

Solution 45:
No, it is not possible to heat a liquid or gas from above because the transfer of heat through convection takes place vertically upwards in liquids and gases. So if they are heated from above, the liquid or gas at the top will only be heated because most liquids and gases are themselves bad conductor of heat so they cannot conduct heat from top layer to the bottom layer.

Solution 46:

• Water is heated generally from below because water itself is a bad conductor of heat and the transfer of heat through convection take place vertically upwards.
• Land becomes warmer than water during the day because water has more specific heat capacity so it absorbs the heat and heats up slowly but on the other hand land has less specific heat and it heats up faster than water.

Solution 47:
Main characteristics of thermometric substance are

• The substance should have high coefficient of expansion so that it is sensitive to the smallest change in temperature
• The substance should have uniform expansion all over its entire volume
• The substance should have minimum specific heat so that it absorbs minimum heat from the body under measurement.

Solution 48:
Wood is an insulator of heat.

Solution 49:

• In cold countries, windows are provided with two glass panes because in between these two glass panes, a thin layer of air is present: air being a bad conductor obstructs the conduction of heat from the room to outside.
• 1 calorie = 4.2 joules
• Yes, it is possible to boil water in a thin paper cup because when heated the heat in the paper cup is transferred to the water through convection and paper cup doesn’t get sufficient heat to get burnt

Solution 50:
Thermometer works on the principle that substances expand on heating and contract on cooling. So we use a thermometric substance which expands and contracts uniformly.

Solution 51:
Advantages of mercury and alcohol as thermometric liquid are

• They both are good conductors of heat.
• They have high coefficient of expansion thus are sensitive to the smallest change in temperature
• Their freezing points are very low and boiling point is high in case of mercury

Disadvantages

• Alcohol is transparent and this makes hard to read the thermometer.
• It does not have uniform expansion.
• Mercury is less sensitive than alcohol as its coefficient of expansion is less than alcohol.
• Alcohol is a volatile liquid.

Solution 52:
Lower point of a thermometer is the temperature at which ice starts melting at normal atmospheric pressure i.e. 0°C
Upper point of a thermometer is the temperature at which water just starts boiling at normal atmospheric pressure i.e. 100°C.

Solution 53:

Solution 54:

• Laboratory thermometer is used to measure and observe the temperature of various chemical reactions
• Clinical thermometer is used to measure human body temperature
• Six’s maximum and minimum thermometer is used in meteorology and horticulture.

Solution 55:

Solution 56:
The temperature that is common in both clinical and Fahrenheit scale is -40°C
Derivation is as follows
Let the temperature be x
C/100= (F – 32)/180
x/100 = (x-32)/180
x * 180/100 = x-32
9/5 x = x – 32
-4/5 x =32
x = – 40

Solution 57:

• 60°C
  60/100 = (F-32) / 180
  F = 6 x 18 +32
  = 110°F
• 100°C
  100/100 = (F – 32) /180
  F = 180 x 1 + 32
  = 212°F
• -40°C
  -40/100 = (F – 32) /180
  F = -4 x 18 + 32
  = 40°F
• 85°C
  85/100 = (F – 32) /180
  F = 85 x 18/10 +32
  = 185°F

Solution 58:

• 104°F
  C = (F – 32) x 100/180
  C = 72 x 100/180
  = 40°C
• 95°F
  C = (F – 32) x 100/180
  = 63 x 10/18
  = 35°C
• 113°F
  C = (F – 32) x 100/180
  = 81 x 10/18
  = 45°C
• 32°F
  C = (F – 32) x 100/180
  = 0 x 10/18
  = 0°C

Solution 59:

Solution 60:
Three modes of heat transfer are

• Conduction involves the transfer of heat from the hot end to the cold end from particle to particle of the medium.
• Convection is the transfer of heat from one body to another by actual movement of the particles of the medium
• Radiation is the transfer of heat from one body to another without the need of an intervening material medium

Solution 61:

Solution 62:

Solution 63:
A wooden knob and a metal latch are both being at same temperature but it feels colder to touch the latch because metal is a good conductor and as soon as we touch it heat from our hand flows to the latch and we feel cold while on the other hand wood is a bad conductor of heat, heat of our hand does not flow into it therefore it does not feel cold.

Solution 64:
The flask consists of double walled glass container with vacuum between the walls A and B to prevent heat loss due to conduction and convection as vacuum is the excellent insulator .to prevent heat loss by radiation, the inner side of the wall A and outer side of wall B is silvered. It has a narrow mouth which is closed by a non-conducting rubber stopper.

Solution 65:
The spiral starts moving because due to the flame of the candle the spiral heats up and expands. While expanding, the spiral tries to create space for the extension in length and an outward pull is created which causes the spiral to move.

Solution 66:

• In winters, the human body covered with a blanket keeps warm because the blanket has air trapped in it which provide heat insulation to the body from the surroundings and keep us warm
• It is better to use two thin blankets to keep the body warm rather than using a single blanket of equal thickness because in between the two thin blankets there is more air trapped than in the single blanket of equal thickness so using two thin blankets better heat insulation is provided to the body from the surroundings and keep us warm
• In winter the birds fluff their feathers in order to trap air in their feathers so that the air provides heat insulation to their body from the surroundings and keep them warm and save them from winter.
• Old quilts are less warmer than new ones because the cotton in the old quilt gets compressed and very little air will remain trapped in it, hence heat insulation is quite poor
• People wear light colured clothes in winter because these clothes reflect most of the sun’s radiations and absorb only a little of them. Therefore, they keep themselves cool.

PAGE NO : 231
Solution 67:
Transformation of Sun’s energy in sun-eco system through a food chain is called energy flow.

Solution 68:

Solution 69:
Any energy transfer is not 100% because energy is lost to the surroundings in the form of heat, friction losses during the transfer of energy. Therefore complete energy is not transferred.

Solution 70:
Bio gas is produced by the action of bacteria on decaying organic matter. The primary source of bio gas in villages is dung of cow, or buffalo. The bio gas is mostly methane which can be used as a chief source of light and heat energy.

Solution 71:

Solution 72:

Solution 73:

Solution 74:

PAGE NO : 232
Solution 75:

Solution 76:
Water is not used as a thermometric liquid because It has low coefficient of expansion so it is less sensitive to temperature changes. Moreover, It is transparent thus making it difficult to read the thermometer and water evaporates with time thus producing error and also the freezing and boiling points are also low.

Solution 77:
The sensitivity of a thermometer can be increased by using a substance having high coefficient of expansion and uniform expansion so that its expands with the slightest change in temperature.

Solution 78:

• When hot water is poured into a thick glass tumbler, it generally cracks because on pouring hot water in the tumbler the inner surface heats up and expands more as compared to its outer surface. This unequal expansion between the two surfaces causes a strain and the tumbler cracks.
• Pyrex glass tumbler does not crack on adding hot water because Pyrex glass has low coefficient of expansion. It does not expand less when hot water is added to the tumbler.

Solution 79:

Solution 80:

Solution 81:

Solution 82:
Temperature in °C = 1°C
C/100 = (F-32)/180
F = 1 x 18/10 + 32
= 33.8°F

Solution 83:
Lower fixed point = 10°C
Upper fixed point =130°C
Range of thermometer= 130°C – 10°C = 120°C
No of divisions = 100
So least count = 120/100 = 1.2°C
On actual thermometer 40°C would have 40 divisions
So, on this thermometer it would show = 40 x LC = 48°C

Solution 84:
The green house is referred to a glass house. The heat enters the house but cannot escape out, because the glass reflects the heat back to the inside of the house. This makes glass house warmer than the outside environment. This phenomenon is called green house effect.

Solution 85:
Global warming occurs due to the presence of carbon di oxide, CFCs, methane in the atmosphere. Carbon dioxide acts as a transparent gas to incoming shortwave radiations which the earth re-radiates into space. It, therefore traps the outgoing radiations thus warming lower atmosphere of the earth thereby causing global warming.

Solution 86:
Harmful effects of global warming are

• The atmospheric temperature of earth would increase thereby making it difficult for a living being to survive
• It would melt down the polar caps thus increasing the size of the ocean and leading to floods, tsunami, etc.
• The increase in temperature would affect climate and rainfall thus affecting flora and fauna.
• Human beings would be vulnerable to diseases as microbes would get warmth to grow.

Solution 87:
The temperature in a green house rises because heat enters the house through the glass but cannot escape out, because the glass reflects the heat back to the inside of the house. This makes glass house warmer than the outside environment.

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