Frank ICSE Solutions for Class 10 Chemistry – Metals and Non-metals

Frank ICSE Solutions for Class 10 Chemistry – Metals and Non-metals

PAGE NO : 151
Solution 1:
Frank ICSE Solutions for Class 10 Chemistry - Metals and Non-metals 1

Solution 2:
Frank ICSE Solutions for Class 10 Chemistry - Metals and Non-metals 2

Solution 3:
Metal which exist in liquid state is mercury.
Non-metal which exist in liquid state is bromine.
Concept Insight: Metals are usually solid while non-metals exist in all the three states.

Solution 4:
The most abundant metal in the earth’s crust is aluminium and the most abundant non-metal in the earth’s crust is oxygen.

Solution 5:

  1. Metals.
  2. Non-metals.
  3. Platinum and Gold.
  4. Potassium and Sodium.
  5. Potassium, Sodium and Calcium.
  6. Iron.
  7. Potassium and Sodium.
  8. Platinum.
  9. Platinum and Gold.
  10. Mercuric oxide (HgO) and Silver oxide (Ag2O).
  11. Potassium hydroxide (KOH) and Sodium hydroxide (NaOH).
  12. Potassium carbonate (K2CO3) and Sodium carbonate (Na2CO3).
  13. Potassium carbonate (K2CO3) and Sodium carbonate (Na2CO3).
  14. Potassium nitrate (KNO3) and Sodium nitrate (NaNO3).
  15. Mercuric nitrate (Hg(NO3)2) and silver nitrate (AgNO3)

Solution 6:
Frank ICSE Solutions for Class 10 Chemistry - Metals and Non-metals 3

Solution 7:

  1. Fe < Zn < Mg < Na.
  2. Na = Al < Cu<Fe
  3. Ca >Mg > Fe > Cu.

Solution 8:
Frank ICSE Solutions for Class 10 Chemistry - Metals and Non-metals 4

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Frank ICSE Solutions for Class 10 Chemistry – Electrolysis

Frank ICSE Solutions for Class 10 Chemistry – Electrolysis

PAGE NO : 131
Solution 1:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 1

Solution 2:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 2

Solution 3:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 3

Solution 4:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 4

Solution 5:
Three appilications of electrolysis are:

  1. Electro plating with metals
  2. Electrofining of metals
  3. Extraction of metals

Solution 6:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 6
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 7

Solution 7:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 8

Solution 8:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 9

Solution 9:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 10

PAGE NO : 132

Solution 10:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 11

Solution 11:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 12

Solution 12:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 13

Solution 13:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 14

Solution 14:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 15

Solution 15:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 16

Solution 16:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 17

Solution 17:
The main appilications of electrolysis are:

  1. Electro plating with metals
  2. Electrofining of metals
  3. Extraction of metals

Solution 18:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 18

Solution 19:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 19

Solution 20:

  1. Na2CO3
  2. NH3
  3. Graphite, Cu electrode
  4. NH4+
  5. Graphite

PAGE NO : 133
Solution 1994-1:

  1. The article to be plated must be made Cathode.
  2. The ions of the metal which is to be electroplated must be present in the electrolyte.
  3. The metal to be plated on the article must be made anode. It needs to be periodically replaced.

Solution 1994-2:
The passage of electricity through an electrolyte occurs through ions furnished by the electrolyte where as the passage of electricity through a copper wire occurs through electrons.

Solution 1995-1:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 20

Solution 1995-2:
It is the process of decomposition of an electrolyte in the molten or aqueous state by discharge of ions at the electrodes on the passage of an electric current.

Solution 1995-3:
Pure water does not conduct electricity because the degree of ionization is low. Thus to make it a good conductor of electricity acid is added to it which will increase the degree of ionization.

Solution 1996-1:
Substance which contain

  1. Ions only:- HCl
  2. Molecules only:- Petrol
  3. Both ions and molecules:- CH3COOH

Solution 1996-2:

  1. Electrolyte is a compound which either in aqueous solution or in molten state allows an electric current to pass through it and is accompanied by discharge of ions and finally into neutral atoms at the two electrodes.
  2. Non- electrolyte are substances which do not conduct electricity in fused or aqueous state. They contain only molecules and do not ionize. For example: petrol, alcohol.
  3. If the electrolyte is described as ‘strong electrolyte’ it means it completely dissociates into its constituting ions in aqueous solution.

Solution 1996-3:

  1. As for every copper ion discharged at the cathode, an ion of copper is formed at the anode which goes into the solution .Since atoms of copper are deposited at the cathode, the cathode becomesthicker and as the atoms of copper from the anode change into ions of copper, the anode becomes thinner.
  2. When platinum rods are used as electrodes, then x the blue colour of copper sulphate solution fades and sulphuric acid is formed. This is because oxygen is liberated at anode and copper metal is deposited at cathode
  3. Practical application of electrolysis of copper sulphate solution: This is the basis for purification of copper.
    Other metals like Zinc, Nickel, Silver .Lead can also be purified.

Solution 1997-1:
Lead Bromide should be in the molten state if it has to conduct electricity.

Solution 1997-2:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 21

Solution 1997-3:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 22

Solution 1998-1:

  1. Electrolyte
  2. Nickel
  3. Cathode
  4. Anode
  5. Cations

PAGE NO : 134
Solution 1999-1:
The electrolysis of lead bromide liberates lead at cathode and bromine at anode.

Solution 1999-2:
When a fused metallic chloride is electrolyzed, the metal is obtained at cathode.

Solution 2000-1:

  1. Strong electrolytes – dilute hydrochloric acid, dilute sulphuric acid, Ammonium chloride
  2. Weak electrolyte – Acetic acid, Ammonium hydroxide
  3. Non-electrolytes – Carbon tetrachloride

Solution 2002-3:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 23

Solution 2002-1:

  1. molecules.
  2. will not

Solution 2002-2:

  1. When sulphuric acid is added to water it becomes good conductor as addition of sulphuric acid causes dissociation of water molecules into H+ and OH– ions which are then responsible for conduction of electricity by pure water. The water thus obtained is called acidified water.
  2. Cathode, Anode

Solution 2003-1:
electricity, chemical

Solution 2004-2

  1. Molecules are found in a liquid compound which is a non-electrolyte.
  2. Non ionized molecules;
  3. H+ and X– particles will be present in dilute solution.
  4. Loss, Gain
  5. The ions of the metal which is to be electroplated on the article must be present in a solution.
  6. Redox reaction is one in which oxidation and reduction occurs simultaneously.
  7. Similarly in case of electrolysis:
    • At cathode: The cations gain electron and become neutral. As the electrons are gained the ion is said to be reduced.
    • At anode: The anions lose electron to form neutral atoms. As the electrons are lost the ion is said to be oxidized.
      Hence in electrolysis also the oxidation and reduction occurs hence it is an example of Redox reaction.

Solution 2004-1:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 24

PAGE NO : 135
Solution 2005-1:

  1. Copper metal is solid and has no mobile ions whereas an electrolyte should dissociate into oppositely charged ions to conduct the electric current.
  2. Hydrogen is released at the cathode when acidulated water is electrolyzed.
  3. In sodium chloride, Na+ and Cl– ions are not free to carry the electric current.
  4. (a) Reduced
    (b) Higher

Solution 2006-1:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 25

Solution 2006-2:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 26

Solution 2007-1:

  1. Molten ionic compound – Strong electrolyte
  2. Carbon tetrachloride- Non-electrolyte
  3. An aluminium wire- Metallic conductor
  4. A solution containing solvent molecules, solute molecules and ions formed by the dissociation of solute molecules- weak electrolyte
  5. A sugar solution with sugar molecules and water molecules- Non-electrolyte

Solution 2007-2:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 27

PAGE NO : 136
Solution 2008-1:
(d) Lead is deposited at the cathode

Solution 2008-2:
Frank ICSE Solutions for Class 10 Chemistry - Electrolysis 28

Solution 2009–2:
Mg (OH)2 as it is basic while rest are amphoteric.

Solution 2009–3:
Molten Lead bromide conducts electricity.

Solution 2009-4:

  1. Nickel ions move towards cathode.
  2. Nickel ions.

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Frank ICSE Solutions for Class 10 Chemistry – Mole Concept And Stoichiometry

Frank ICSE Solutions for Class 10 Chemistry – Mole Concept And Stoichiometry

PAGE NO : 103
Solution 1:

  1. Gay-Lussac’s law: It states that ‘when gases react, they do so in volumes which bear a simple ratio to one another, and also to the volume of the gaseous product, provided all the volumes are measured at the same temperature and pressure’.
  2. Avogadro’s law : It states that ‘Under the same conditions of temperature and pressure, equal volumes of all gases contain the same number of molecules’.

Solution 2:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 1

Solution 3:
When stating the volume of a gas, the pressure and temperature should also be given because the volume of a gas is highly susceptible to slight change in pressure and temperature of the gas.

Solution 4:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 2

Solution 5:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 3

Solution 6:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 4

Solution 7:

  1. Gram atom: “The quantity of the element which weighs equal to its gram atomic mass is called one gram atom of that element”.
    For example: The gram atomic mass of hydrogen is 1g. So, 1g of hydrogen is 1 gram atom of hydrogen.
  2. Gram mole: “A sample of substance with its mass equal to its gram molecular mass is called one gram molecule of this substance or one gram mole”.
    For example: Gram molecular mass of oxygen is 32 g. So One gram mole of oxygen is 32g.

Solution 8:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 5

Solution 9:
Empirical formula:“Empirical formula of a compound is the formula which gives the number of atoms of different elements present in one molecule of the compound, in the simplest numerical ratio”.
Molecular formula: “Molecular formula of a compound denotes the actual number of atoms of different elements present in one molecule of the compound”.

Solution 10:

  1. The empirical formula of C6H6 is: CH
  2. The empirical formula of C6H12O6 is: CH2O.
  3. The empirical formula of C2H2 is: CH
  4. The empirical formula of CH3COOH is: CH2O.

Solution 11:
Three pieces of information conveyed by the formula H2O is that:

  1. It shows that there are 2 hydrogen atoms and 1oxygen atoms present in H2O.
  2. The hydrogen and oxygen atoms are present in simplest whole number ratio of 2:1.
  3. It represents one molecule of compound water.

Solution 12:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 6

Solution 13:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 7

PAGE NO : 104

Solution 14:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 8

Solution 15:

  1. Na2SO4.10H2O.
  2. C6H12O6.

Solution 16:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 9

Solution 17:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 10

Solution 18:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 11

Solution 19:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 12

Solution 20:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 13

Solution 21:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 14

Solution 22:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 15

Solution 23:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 16

Solution 24:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 17

PAGE NO : 105
Solution 25:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 18

Solution 26:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 19

Solution 27:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 20

Solution 28:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 21

Solution 29:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 22

Solution 30:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 23

Solution 31:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 24

Solution 1996-1:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 25

Solution 1996-2:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 26

Solution 1996-3:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 27

Solution 1996-4:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 28

PAGE NO : 106
Solution 1997-1:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 29

Solution 1997-2:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 30

Solution 1997-3:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 31

Solution 1997-4:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 32

Solution 1998-1:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 33

Solution 1998-2:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 34

Solution 1999-1:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 35

PAGE NO : 107

Solution 1999-2:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 36

Solution 1999-3:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 37

Solution 2000-2:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 38

Solution 2000-1:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 39

Solution 2000-1:
Gay – Lussac proposed this law.

Solution 2001-2:
Molecular mass of ethane = 30
According to Gay-Lussac’s law:
2 vol. of C2H6 requires= 7 vol. of oxygen
Vol. of C2H6 = 2 vol. = 100 L
Vol. of oxygen required = 7 vol. =350 L

Solution 2001-3:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 40

PAGE NO : 108
Solution 2001-4:
The term is vapour density.

Solution 2001-5:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 41

Solution 2001-6:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 42

Solution 2001-7:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 43

Solution 2002-1:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 44

Solution 2002-2:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 45

Solution 2002-3:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 46

Solution 2003-1:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 47

Solution 2004-1:

Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 48

PAGE NO : 109
Solution 2004-2:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 49

Solution 2005-1:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 50

Solution 2006-1:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 51

Solution 2006-2:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 52

PAGE NO : 110
Solution 2006-3:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 53

Solution 2006-4:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 54

Solution 2007-1:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 55

Solution 2007-2:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 56

Solution 2008-1:
The gas laws which relates the volume of a gas to the number of molecules of the gas is avogadro’s law

PAGE NO : 111
Solution 2008-2:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 57

Solution 2008-3:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 58
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 59

Solution 2009-2:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 60

Solution 2009-3:
The correct statement is that equal volumes of all gases under identical conditions contain the same number of molecules.

Solution 2009-4:
Frank ICSE Solutions for Class 10 Chemistry - Mole Concept And Stoichiometry 61

Solution 2009-1:
The relative molecular mass of the gas is 10.

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Frank ICSE Solutions for Class 9 Physics – Electricity and Magnetism

Frank ICSE Solutions for Class 9 Physics – Electricity and Magnetism

PAGE NO: 323
Solution 1:
Positive and negative are the two kind of charges.

Solution 2:
Net charge on an atom is zero.

Solution 3:
10 is the number of electrons present in Na+.

Solution 4:
An atom does not have any net charge while ion is either a positive charge or a negative charged.

Solution 5:
The friction between two bodies when they are rubbed against each other is the reason of electrification.

Solution 6:
A lightening conductor is a device used to protect the large buildings against lightening during a thunderstorm.

Solution 7:
The speed of light is very fast as compared to the speed of sound in air. So, the thunder is seen fast and then we hear the sound of thunderstorm.

Solution 8:
Electroscope is used to determine the nature of the charge and to detect the presence of charge on the body.

Solution 9:
When a positively charged rod is brought near the positively charged cap then , the positive charge on the cap will spread over because of repulsion and some of them will reach to the leaves . Now, the leaves will have the same positive charge , they will repel each other and hence, leaves will diverge.

Solution 10:
The flow of electrons in a particular direction is called direct current.

Solution 11:
The two differences between primary and secondary cell are :

  • Primary cells cannot be charged again while secondary cells can be charged again and again.
  • In primary cells, chemical reaction is irreversible while in secondary cells , chemical reaction is reversible.

Solution 12:
S.I. unit of current is ampere.

Solution 13:
A battery is the made up of multiple cells.

Solution 14:
Current is a scalar quantity.

Solution 15:
Current is defined as the rate of flow of charge.

Solution 16:
A milliampere is bigger than microampere.

Solution 17:
Rheostat is other name of variable resistor.

Solution 18:
A cell and battery are the two sources of current.

Solution 19:
No, voltmeter is not the same as voltameter.

Solution 20:
Ammeter is used to measure the magnitude of current in the circuit.

Solution 21:
Electrons flow inside the metallic conductor and a battery and cell helps in the movement of electrons in it.

Solution 22:
Voltmeter has high resistance than the ammeter.

Solution 23:
An artificial magnet is the magnetized piece of iron or steel.

Solution 24:
Voltmeter is always connected in parallel to the circuit.

Solution 25:
Ammeter is always connected in series in the circuit.

Solution 26:
S.I unit of resistance is ohm.

Solution 27:
The resistance of conductor is 1 ohm when a current of 1 ampere flows through it when the potential difference across it is 1 volt.

Solution 28:
I = Q/t = 0.8/5 = 0.16 Ampere.

Solution 29:
Rheostat is an instrument to control the current in the circuit.

Solution 30:
Horse-shoe magnet is the shape of the magnet. This shape helps in bringing the poles near to each other and make the strong magnet.

Solution 31:
The magnetism acquired by a magnetic material when it is kept near a magnet is called induced magnetism.

Solution 32:
The points of the magnet where attraction appears the maximum are called poles of magnet and they are situated at ends of the magnet.

Solution 33:
The differences between primary and secondary cell are :

  • Primary cells cannot be charged again while secondary cells can be charged again and again.
  • In primary cells, chemical reaction is irreversible while in secondary cells , chemical reaction is reversible.

Solution 34:
A cell is a source of energy which converts the chemical energy into electrical energy. The cell consists of two electrodes in the form of conducting rod immersed in the solution called electrolyte.

Solution 35:
I = Q/t = n e/t
So, n = I.t / e = 1. 1 / 1.6 x 10-19 = 6.25 x 1018
So, 6.25 x 1018 will be the number of electrons.

Solution 36:
Q = I.t = 4.5 x 2.5 = 11.25 C.

Solution 37:
A key is used to put the current on and off in the circuit.

Solution 38:
The effect to rate of flow of current by the wire is called its electrical reistance. Its S.I unit is ohm.

Solution 39:
The resistance of the wire depends on the following factors :

  • Length of the wire
  • Cross-section of the wire
  • Temperature of the wire.
  • Material of the wire.

Solution 40:
With increase in temperature of the wire, the resistance of wire increases.

Solution 41:
The resistance of wire will become 4ohm.

Solution 42:
Variable resistors consist of a resistance track with connections at both ends and a wiper which moves along the track as you turn the spindle. The track may be made from carbon, cermet (ceramic and metal mixture) or a coil of wire (for low resistances). The track is usually rotary but straight track versions, usually called sliders, are also available.
A variable resistance is a device used to change the resistance and hence the current flowing through a circuit; without changing the voltage.
Frank ICSE Solutions for Class 9 Physics - Electricity and Magnetism 1

Solution 43:
Galvanometer is used to detect the direction of current as well as to detect very weak current. Ammeter is used to measure the magnitude of an electric current in the circuit.

Solution 44:
Voltmeter is used to measure the potential difference between two points in the circuit. Voltameter is an instrument for measuring the voltaic electricity passing through it, by its effect in decomposing water or some other chemical compound acting as an electrolyte.

Solution 45:
The magnets (pieces of lodestone) found in nature is called natural magnet. The properties of magnet are :

  • Attractive propery
  • Directive property
  • like poles repel while unlike poles attract.

Solution 46:
Frank ICSE Solutions for Class 9 Physics - Electricity and Magnetism 2

Solution 47:
The mechanism in which magnetism acquired by the magnetic material when kept near a magnet is called magnetic induction. When the magnetic material get magnetized, the pole developed on its side will be opposite to the magnet’s pole taken near to it. So, opposite poles attract each other. So, induction causes attraction.

Solution 48:
We will start drawing the magnetic field of lines from the north pole of magnet. When a small compass is placed at a point near the north pole of the magnet , the needle turns round on its pivot and settle in the fixed direction. At other points away from the pole the needle settles tangent to the drawn field line. By plotting the directions indicated by the needle, we can draw magnetic field of lines.

Solution 49:
Frank ICSE Solutions for Class 9 Physics - Electricity and Magnetism 3

PAGE NO : 324
Solution 50:
The magnetic field of lines are the lines which get formed by joining the poles of the magnet and they are the continuous curves in which tangent drawn to it will give the direction of magnetic field.

Solution 51:
By breaking the magnet into two halves, magnetic strength will always get half.

Solution 52:
By breaking the magnet into two halves, magnetic strength will always get half. So, the raio of magnetic strength will be 1:2.

Solution 53:

  • The charge gained by the B will be positive charge
  • The B will be charged by the charging by contact. The charge on A will spread on B.

Solution 54:
Electroscope is the device used to detect the presence of charge and the nature of charge on the body. The four stages of the charging a gold leaf electroscope by induction are :
(i) Bring a positively charged rod near the cap of an electroscope. The cap will acquire the negative charge on it by induction. The leaves will diverge
(ii) Earth the electroscope by touching the cap will finger.
(iii) Remove the finger and keep the positively charged rod as such.
(iv) Now, take away the rod. The leaves will diverge because of charges induced by induction.
Frank ICSE Solutions for Class 9 Physics - Electricity and Magnetism 4

Solution 55:
Electrostatic induction is the process of charging a body by bringing another charged body near to it. When the X will come near to body B, the opposite charge will be acquired by body B. So, negative charge will be acquired. Similarly, by electrostatic induction, A will acquire the opposite charge of B so A will acquire the positive charge.

Solution 56:

  1. Lightening conductor is a device used to safeguard the large buildings against lightening of thunderstorm. Normally, they are fitted on the top of tall buildings as a safety device. It consist of few metal spikes fitted to the highest part of building and connected to thick copper strip which is buried inside the earth .
    • Resistance of the conductor: It is the property of the conductor by virtue of which it obstructs the flow of current in the circuit.
    • Potential Difference: It is defined as the amount of work done in moving a charge from one point to another .
    • Open Circuit: In the circuit, if the switch is off or the wire is cut then flow of current in circuit stops and we say that its an open circuit.
    • Closed Circuit: The circuit in which current flows without any obstruction then it’s a closed circuit.

Solution 57:

  • When two bulbs will connect in series then resistance of the circuit will increase so the brightness of the bulbs will decrease.
  • When the two bulbs will be connected in parallel then resistance of circuit will decrease so the bulbs brightness will increase.

Solution 58:

  1. Differences between Conductor and insulators::
    • Conductors allow passing of electric current through it. Insulator does not allow passing of current through it.
    • Silver, Gold are good examples of conductor of electricity. Rubber, Cotton are good examples of insulators.
  2. Flow of electrons is the flow of negative charges inside the conductor while flow of conventional current is the flow of positive charges inside a conductor.
  3. Primary cells are the cells in which chemical reaction is irreversible so they can’t be charged again and again. While , secondary cells are the cells in which chemical reaction is reversible and can be charged again and again.

Solution 59:

  1. Following are the properties of magnet
    • Like poles of magnet repel each other while unlike poles attract.
    • Magnet have an attractive property means it attract the magnetic material towards it.
    • Magnet have the directive property means when it is held freely , it always point towards north-south direction.
  2. The Laws of Magnetism: Like poles repel each other and unlike poles attract each other.
    • Magnetic materials get attracted towards the magnet but non-magnetic materials does not get attracted towards the magnet.
    • Natural magnets are the pieces of lodestone which are found in nature while artificial magnet is the magnetized piece of iron or steel.
    • Iron has high susceptibility and low retentivity means it acquires the magnetism faster and removes it soon as well. While , steel has low susceptibility and high retentivity.

Solution 60:
Frank ICSE Solutions for Class 9 Physics - Electricity and Magnetism 5

PAGE NO : 325
Solution 61:

 

  1. Magnetic induction is the process in which magnetism is acquired by the magnetic material when a magnet is brought near it.
    • If we had a magnet then we will bring the magnet near to steel , if there is force of repulsion or attraction is experienced then steel was magnetized otherwise not.
    • We will held the steel freely, if it points to north-south direction only then it is magnetized otherwise not.
    • Magnetic Meridian: It is the vertical plane containing the magnetic axis of a freely suspended magnet at rest under the earth’s field.
    • Geographic Meridian: It is the vertical plane containing the geographic north and south poles of the earth and passing through the given place in the surface of earth.
    • Angle of declination: The angle between geographic and magnetic meridian is called angle of declination.
    • Angle of Dip: The angle between the horizontal and earth’s magnetic field is known as angle of dip.

Solution 62:

  • When a nylon shirt , blouse or stocking s are removed then they get rubbed with the hairs and due to friction between hairs and nylon, charges get induced on them and attractive force get induced between them.
  • The rubbed ebonite rod contains more electrons so it acquires the negative charge so a charged is acquired by it. But, in the rubbed metal rod , electrons are transferred but through hands and body they pass to the earth so no charges will be there while metal rod is held in hand.
  • Soft iron is used to make electromagnets because it has high susceptibility and low retentivity , it get magnetized very faster and loses magnetism as soon as the inducing magnet is removed.
  • Two steel needles hanging from the lower end of the vertical bar magnet do not hang vertical but will diverge because they got the like poles on it and like poles repel each other so they diverge.
  • If magnetic material is brought near to the magnet then it get attracted although its not magnetized but the magnetic material will be repelled only in case it is magnetised. So repulsion is the sure test of magnetism.

Solution 63:
Frank ICSE Solutions for Class 9 Physics - Electricity and Magnetism 6

Solution 64:
Disadvantages of setting up large dams for hydro-electricity power station::

  • It leads to large catchment area being submerged
  • displacement of people from their places.

Solution 65:
Improved practices in the use of energy :

  • Use the improved cook stove which will save the bio-mass energy
  • Use the improved solar panels and solar furnaces.

Solution 66:
The functions of bureau of energy efficiency setup are :

  • control and keep an eye on consumption pattern
  • develop appliances suitable for the energy change
  • organize posters and slogans for developing awareness in society.

Solution 67:

  • At School: Use of solar cells to light up the electricity in schools and do rain water harvesting, keep the electrical appliances off after the needed period of time.
  • At Home: Use of bio energy for cooking and lightening, use CFLs instead of filament bulbs, keep the electrical appliances off after the needed period of time.

Solution 68:
Frank ICSE Solutions for Class 9 Physics - Electricity and Magnetism 7
Frank ICSE Solutions for Class 9 Physics - Electricity and Magnetism 8

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Frank ICSE Solutions for Class 9 Physics – Electricity and Magnetism: Magnestism

Frank ICSE Solutions for Class 9 Physics – Electricity and Magnetism: Magnestism

PAGE NO: 320
Solution 1:
Natural magnet is the deposits of the iron ore which has the attracting property of iron The properties of natural magnet are :

  • The magnet has the directive property, when it is suspended freely , it always come in north-south direction.
  • A magnet attracts magnetic substances like iron, steel etc. so, it has the attractive poperty.
  • Like poles repels each other while unlike poles attract each other in magnet.

Solution 2:
Artificial magnets are the magnets which are formed by bringing the natural magnet near it The artificial magnets have the high retentivity means they remains magnetized for the long period of time and that is why they are used for making strong electromagnets.

Solution 3:
The magnetic forces appear to be concentrated at the near ends of the magnet. These points are called the magnetic poles.

Solution 4:
Bring the rod near the magnet, iron rod will get attract towards the magnet while copper will not.

Solution 5:
Suspend a magnet freely; it will always point towards the north -south direction. The pole of the magnet which point towards the north is called north pole and the pole which point towards south is called south pole.

Solution 6:
Magnetic axis: The imaginary line joining the poles of the magnet is called magnetic axis.
Poles of the Magnet: The points of the magnet where the attraction appears to be maximum are called poles of the magnet.
Effective Length of the magnet: The distance between the poles of magnet is the effective length of magnet.

Solution 7:
Suspend the iron bar and magnet freely in the space by using thread. And, move them here and there few number of times. The bar which always points in north south direction after coming to rest is a magnet and other bar is the iron bar.

Solution 8:
No, we cannot isolate the poles of the magnet.

Solution 9:
The magnetism acquired by the magnetic material when it is kept near the magnet is called induced magnetism.

Solution 10:
The lines of the magnetic field are the continuous curve such that the tangent drawn at any point gives the direction of magnetic field at that point.

Solution 11:
The natural magnet which was used for the navigation by the mariners is called lodestone.

Solution 12:
Magnetic compass is used to draw the magnetic field of lines around the magnet.

Solution 13:
No, Magnetic field of lines cannot intersect each other.

Solution 14:
Frank ICSE Solutions for Class 9 Physics - Electricity and Magnetism Magnestism 1

Solution 15:
The simple experiment to show that like poles repel while unlike poles attract each other is : Suspend a bar magnet and allow it to freely rotate. When it will come to rest, it will point towards the north south direction. Now, bring the N pole of second magnet near the North pole of the suspended magnet , we will see repulsion between the two magnets. But, if we bring south pole of second magnet near the north pole of suspended magnet then we will observe attraction. So, we can say like poles repel while unlike poles attract.

Solution 16:
The directions indicated by the needle of compass will help to draw the magnetic lines of force.

Solution 17:
Neutral points are the points where the magnetic field of magnet has the magnitude equal to the magnitude of earth’s magnetic field but in opposite direction.

Solution 18:
Neutral points help in finding the magnitude and direction of earth’s magnetic field at that particular point.

Solution 19:
The resultant magnetic field at neutral point is zero.

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Frank ICSE Solutions for Class 9 Physics – Electricity and Magnetism: Current Electricity

Frank ICSE Solutions for Class 9 Physics – Electricity and Magnetism: Current Electricity

PAGE NO: 312
Solution 1:
The flow of electrons in a particular direction in a conductor is called an electric current.

Solution 2:
An electric cell is the source of electric current in which chemical energy changes to electrical energy.

Solution 3:
The charge on an electron is -1.6 x 10-19 C.

Solution 4:
The constituents of cell are two electrodes in the form of conducting rods immersed in the solution called electrolyte.

Solution 5:

  • S. I unit of electric current is Ampere
  • S.I unit of potential difference is volt.
  • S.I unit of resistance is ohm.

Solution 6:
I = 1A
T = 1s.
I = Q/t = ne/t
So, n = I.t/e = 1.1/(1.6 x 10-19) = 6.25 x 1018 electrons.

Solution 7:
I = Q/t = 0.7 / 7 = 0.1 Ampere.

Solution 8:
Rheostat is used to control the current in the circuit.

PAGE NO : 313
Solution 9:
Rheostat is the variable name of electrical resistance.

Solution 10:
Switch is used to put the current on and off in the circuit.

Solution 11:
Frank ICSE Solutions for Class 9 Physics - Electricity and Magnetism Current Electricity 1

Solution 12:
I = Q/ t So, Q = I.t = 1.2 x 3.0 = 3.6 C.

Solution 13:
A – is a voltmeter to measure the potential difference, B is an electric resistance to control the current in the circuit , C is the ammeter to measure the magnitude of an electric current, D is cell to provide electric current in circuit, E is an electric key to on and off the circuit, F is the rheostat to control the current in circuit.

Solution 14:
The slope of the graph represents that with current flowing through a conductor is directly proportional to the potential difference applied the resistance of conductor is constant.

Solution 15:
Potential difference between two conductors is defined as the amount of work done in moving the unit positive charge from one conductor to another through the wire.

Solution 16:
Yes, electric current is a scalar quantity.

Solution 17:
The electric resistance of the wire depends on the following factors :

  • The length of the wire.
  • The area of cross-section of the wire.
  • The temperature of the wire.
  • The material of the wire.

Solution 18:
The S.I unit of resistance is ohm.

Solution 19:
If another bulb is connected in series then the resistance of the wire will increase.
If another bulb is connected in parallel then resistance will decrease.

Solution 20:
V = IR.

Solution 21:
The resistance of the wire is 2 ohms if a current of 1 ampere flows through it when the potential difference across it is 2 volt.

Solution 22:
The current I = V/R = 14/28 = 0.5 Ampere.

Solution 23:
The factors on which resistance of the wire depends are:

  • The length of the wire , resistance is directly proportional to the length of wire.
  • The cross-section of the wire , resistance is inversely proportional to the cross-section of the wire.
  • The temperature of the wire , resistance of wire is directly proportional to the temperature of the wire.
  • The material of the wire (good conductors possess less resistance.)

Solution 24:
W = V.Q = 6.3 = 18 Joule.

Solution 25:
The resistance of the conductor is the property due to which it opposes the flow of current in it.

Solution 26:
The potential difference between two points is 1 volt if the work done in transferring 1 coulomb of charge from one point to another point is 1 joule.

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Frank ICSE Solutions for Class 9 Physics – Electricity and Magnetism: Static Electricity

Frank ICSE Solutions for Class 9 Physics – Electricity and Magnetism: Static Electricity

PAGE NO: 300
Solution 1:
Electrostatics is defined as the study of charges at rest.

Solution 2:
Frictional electricity is also known as static electricity.

Solution 3:
Thales of Miletus was the scientist who observed the electric properties of amber.

Solution 4:
There are two kind of charges – positive and negative charge.

Solution 5:
A positively charged body signifies that its nucleus contains more number of protons than electrons.

Solution 6:
A negatively charged body signifies that it contains number of electrons more than number of protons.

Solution 7:
Benjamin Franklin was the scientist who first assigned the algebraic signs to charges.

Solution 8:
When a glass rod is rubbed with silk,the glass rod acquires the positive charge.

Solution 9:
When ebonite rod is rubbed with cat’s fur, the ebonite rod acquires the negative charge.

Solution 10:
The quantization of charge is the property by virtue of which every charge exists only in discrete lumps or packets of some minimum charge.

Solution 11:
Energy other than electric charge is quantized.

Solution 12:
Q = Ne
N = Q/e = 1C / 1.6 x 10-19 = 6.25 x 1018

PAGE NO : 301
Solution 13:
1C is bigger than charge on an electron.

Solution 14:
Q = Ne
The charge on an electron = -1.6 x 10-19
= 100 x 1.6 x 10-19 = 1.6 x 10-17

Solution 15:
Q = Ne
N = Q/ e = -3.6 x 10-18 /1.6 x 10-19 = 22.5
Since, n is not an integral value so this value of charge is not possible because charge is quantized.

Solution 16:
The origin of frictional forces is electrical in nature.

Solution 17:
The cause of charging is the frictional forces between the two bodied when they are rubbed against each other.

Solution 18:
The Sir Williams Gilbert was the scientist who showed two charges and Benjamin Franklin was the scientist who gave name to charges.

Solution 19:
Two differences between charge and mass are ::

  • Electric charge can be positive , negative or zero while mass of the body is strictly positive.
  • Electric charge is quantized while the quantization of mass is not yet established.

Solution 20:
Yes, mass of the body get affected on charging.

Solution 21:
There will be attractive force between the B and C because both carry opposite charges.

Solution 22:
Unlike charges attract each other and like charges repel each other.

Solution 23:
No, the motion of the object does not affect the charge on the body.

Solution 24:
The properties of an electric charge are

  • Electric charges are quantized.
  • Like charges repel each other while unlike charges attract each other.

Solution 25:
Photons can never have charge because charges never exist without rest mass.

Solution 26:
The silk cloth will acquire the charge opposite to the charge of glass rod . So the charge acquired by silk cloth will be = -1.6 x 10-19 C.

Solution 27:
The S.I unit of charge is coulomb.

Solution 28:
The value of charge on an electron = -1.6 x 10-19 C. No, the charge less than charge of an electron is not possible.

Solution 29:
The net charge on an atom is zero.

Solution 30:
The electrons of the outermost orbit of an atom are the free electrons and they easily leave their respective atoms and become free to move inside the solid.

Solution 31:
An ion is an atom which has either gained one or more electrons or which has lost one or more electrons. When an atom’s valence electrons leave their atom and become free to move inside the solid and move to another atom then positive ion is formed. And, the other atom which gain electrons become the negative ion.

Solution 32:

  • On positive ion, there exist a positive charge.
  • On negative ion, there exists a negative charge.

Solution 33:
If the electrified silk cloth or the ebonite rod are brought near to each other then they will repel each other but when electrified silk cloth and glass rod are brought together then they attract each other. The charges on the electrified silk cloth and ebonite rod is negatives while on glass rod , its positive so we can say that like charges repel each other while unlike charges attract each other.

Solution 34:
When the nylon cloth get rubbed with hairs then it acquires the negative charge because few free electrons get transferred from hairs to nylon and they get attracted towards nylon cloth so the hair stands on their end.

Solution 35:
The charge is quantized and Q = ne where n should be only integer . Since Q = -1.8 e where n is not an integer. So, this charge is not possible.

Solution 36:
Frank ICSE Solutions for Class 9 Physics - Electricity and Magnetism Static Electricity 1

Solution 37:
The purpose of an electroscope is to detect the presence of charge on the body and nature of charge (whether its positively charged or negatively charged) on the body.

PAGE NO : 302
Solution 38:
P is a Cap, Q is plug and R is the bottle in the negatively charged gold leaf electroscope. P is a conductor and Q, R is an insulator.

Solution 39:

  • P will have the positive charge
  • Q will have no charge.
  • Cap of the electroscope will have no charge.
  • The gold leaf will have negative charge.
  • The leaf will diverse because like charges repel each other
  • If electroscope is earthed then metal rod will have positive charge.

Solution 40:
Earthing of an electroscope is meant to take the thick copper strip inside the earth so that charges induced from thunderstorm on the metal spikes can move to earth to safeguard buildings from thunderstorm.

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Frank ICSE Solutions for Class 9 Physics – Sound

Frank ICSE Solutions for Class 9 Physics – Sound

PAGE NO: 286
Solution 1:
Yes, we can hear in the dark room.

Solution 2:
Sound is produced by the vibrating objects.

Solution 3:
Yes, sound is a form of energy.

Solution 4:
No, sound cannot travel through vacuum. It needs a material medium to travel.

Solution 5:
Yes, sound requires a material medium for transmission.

Solution 6:
The speed of sound depends on the following factors: Density of air, Temperature , Humidity in air as well the wind.

Solution 7:
There is no effect on the wavelength and amplitude on the speed of sound.

Solution 8:
Speed of sound at room temperature is 330 m/s

Solution 9:
Yes, the speed of sound is different in different medium.

Solution 10:
No, the speed of sound in the gas is independent on the change in pressure of the gas.

Solution 11:
Frank ICSE Solutions for Class 9 Physics - Sound 1

Solution 12:
Yes, the speed of sound depends on the direction of wind. When wind is blowing in the direction of propagation of sound , the speed of sound increases. But, when wind blows in the direction opposite to that of sound , the speed of sound decreases.

Solution 13:
Ultrasonic are sounds having frequency higher that 20 KHz and not audible to the human being.

Solution 14:
SONAR stands for the “SOund Navigation And Ranging”.

Solution 15:
Ultrasonic sound has higher frequency than infrasonic sound.

Solution 16:
No, we cannot hear the sound produced due to the vibration of second’s pendulum.

Solution 17:
No, SONAR does not make use of infrasonic waves. Instead, it make use of ultrasonic waves.

Solution 18:
Yes, ultrasound in the medium travels faster than the audible sound.

Solution 19:
No, it is not possible to hear the friend’s voice in vacuum because sound needs a material medium to travel.

Solution 20:
The following are the requisites of medium to travel:

  • The medium should possess elasticity so that particles of medium have tendency to come back to their original position after the displacement.
  • The medium should be frictionless so that there should be loss of energy.
  • The medium must possess inertia so that particles of medium have ability to store energy.

Solution 21:
Sound is produced by the vibrating objects. We require a material medium for the propagation of sound because vibrations of object need to get transferred or transmitted from one place to another.

Solution 22:
With increase in temperature of gas, there is increase in speed of gas because increase in temperature decreases the density of gas. And speed of sound is inversely proportional to density of gas. The speed of gas is independent of the pressure of gas.

Solution 23:

  • No, there is no effect of wavelength and amplitude on the speed of sound.
  • With increase in density, there is decrease in the speed of sound in gas.

Solution 24:
Sound is defined as form of energy that produces the sensation of hearing in our ears. The sound travels in medium through energy transfers by wave motion from one place to another. For example , when the prong of the tuning fork vibrate , the waves start moving from one fork to another , the air start getting compressed . The compression is pushed forward. Now, when the fork vibrate in another direction, the air in the immediate neighbor which was compressed, now get rarefied. As a result, a series of compression and rarefactions are produced and sound energy travels in the direction where compression and rarefactions travel.

Solution 25:
The ratio of speed of sound in air to speed of sound in steel is 1/15.

Solution 26:
The distance of observer from the gun = speed of sound x time taken for the explosion = 350 x 2 = 700m

Solution 27:
Yes, light travels faster in air than water. Because, light does not require any medium for their propagation and they are not mechanical waves. The quantities which oscillate in light are mechanical and electric field. And electric and magnetic field decrease with the medium in between them. So, light travels faster in air than water.

Solution 28:
The flash of light reaches earlier than the sound of thunder because the speed of light (its 3 x 108) is much larger than the speed of sound in air (its 330 m/s).

Solution 29:
The sound of 1000 Hz frequency will be audible to us. Others 2Hz is infrasonic sound frequency and 200 KHz, 8 MHz is ultrasonic sound frequency.

Solution 30:
Frank ICSE Solutions for Class 9 Physics - Sound 2

Solution 31:
There is no atmosphere on moon. So, we cannot hear each other on moon because sound needs a material medium to travel from one place to another. No kind of sound can be heard.

Solution 32:
The following are the three characteristics of the medium required for the propagation of sound:

  • The medium must possess elasticity so that the particles of medium have the tendency to return back to their original positions.
  • The medium must be frictionless so that there is no loss of energy during transmission.
  • The medium must possess inertia such that the particles of medium have the ability to store energy.

Solution 33:
The simple experiment that a person can do to calculate the speed of sound in air is that a person stands at a known distance (d meter) from the cliff and fires a pistol and simultaneously start the stop watch. He stops the stop-watch as soon as he hears a echo. The distance travelled by the sound during the time (t) seconds is 2d.
So, speed of sound = distance travelled / time taken = 2d/t

Solution 34:
Ultrasonics sound is the sound having frequency more than 20KHz. The application of ultrasonic sound is as follows:

  • It is used to detect the flaws in metal casting of automobile tyres.
  • Used in hospitals to detect defects in certain parts of body.

Solution 35:
Sound waves are produced by the object motion back and forth in the medium. Due to which it compresses the medium and compression waves are moved forward. The sound travels in medium through energy transfers by wave motion from one place to another. For example , when the prong of the tuning fork vibrate , the waves start moving from one fork to another , the air start getting compressed . The compression is pushed forward. Now, when the fork vibrate in another direction, the air in the immediate neighbor which was compressed, now get rarefied. As a result, a series of compression and rarefactions are produced and sound energy travels in the direction where compression and rarefactions travel.

Solution 36:
Light waves are electromagnetic waves while the sound waves are mechanical waves. Light waves do not require any material medium for their propagation while sound waves need the material medium for its travel from one place to another.
Due to large magnitude of difference between speed of light (i.e 3 x 108 m/s) to the speed of sound in air (330 m/s) , the light reaches first and then the sound from the object. Like, in thunderstorm, the light reaches first to earth and then person hears the sound of light.

Solution 37:

  • Pressure of air: The speed of sound in air is independent of pressure of air.
  • Temperature of Air: Speed of sound in air is directly proportional to the temperature of air. As the temperature of air increases, the density of air decreases and hence speed of sound increases.
  • Humidity: The speed of sound increases with increase in humidity. The increase of moisture decreases the density of the atmosphere and therefore sound travels faster in moist air.
  • Wind: The speed of sound depends on the direction of wind. When the wind is blowing in the direction of propagation of sound, the speed of sound increases. But, when the wind blows in the direction opposite to that of the sound, the speed of sound decreases.

Solution 38:

  • The bat during its flight at night: Bats emits its own distinctive sounds. The echoes of the sound helps bat to navigate and to locate their prey during night.
  • The dolphin to locate small fish as its prey: Dolphins sends the sound having frequencies between 120 KHz to 150KHz. The returning echoes used to help their preys.

Solution 39:
A person hearing at one end of the long metal bar hears two distinct sounds when the other end is struck with a stone because sound comes from the metal bar as well as from air. The sound travels faster in solids than air. So, first sound comes from metal bar hitting and then from air.

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Frank ICSE Solutions for Class 9 Physics – Sound: Range of Hearing

Frank ICSE Solutions for Class 9 Physics – Sound: Range of Hearing

PAGE NO: 284
Solution 1:
The frequency of sound is defined as the number of vibrations produced by the sound producing object per second.

Solution 2:
S.I unit of frequency is hertz.

Solution 3:
One hertz is defined as one vibration produced in one second by sound producing object.

Solution 4:
The audible range of frequency is 20Hz to 20KHz.

Solution 5:

  • Less than 20Hz – we cannot hear sound.
  • More than 20KHz – we cannot hear sound.

Solution 6:
No, the audible range of frequency does not vary from person to person and also with age of person.

Solution 7:
Sound having frequency less than 20Hz is called infrasonic sound. Sound having frequency greater than 20KHz is called ultrasonic sound.

Solution 8:
The energy carried by ultrasonic sound is very high.

Solution 9:
Applications of Ultrasonic sound

  • Ultrasonic sound is used to detect the flaws in metal castings of automobile tyres.
  • It is used in hospitals to detect defects in certain parts of body.

Solution 10:
Echocardiography is used to obtain the image of the heart by the used of ultrasonic waves.

Solution 11:
SONAR stands for Sound Navigation and Ranging. Sonar helps the oceanographers and ship captains to determine the depth of the ocean.

Solution 12:
Bats emit the high frequencies that range between 20 KHz to 75 KHz. The echoes from these sounds help in locating the obstacles in their path and to avoid them.

Solution 13:
The elephants and whales produce the sound of frequency less than 20Hz. (means infrasonic sounds)

Solution 14:
No, all animals does not have same range of audible frequencies.

Solution 15:
When the sound strike any object and reflect back, the hearing of reflected sound is called echo.

Solution 16:
Echolocation is defined as sending out sounds to judge the location, size and motion of objects from the returning echoes. The animals use this phenomenon to locate the obstacles in their path and avoid them so it helps them in navigation and to locate their prey.

Solution 17:
Three Important uses of echolocation:

  • It helps animals to communicate with each other. e.g dolphins use the echolocation to communicate with other dolphins.
  • It helps in navigation and to locate their prey.
  • It is used by them to hunt for the meal.

Solution 18:
A hearing aid is the device which increases the loudness and intensity of the incoming sound.

Solution 19:
The main components of hearing aid are microphone , amplifier and earphone.

Solution 20:
A ship sends ultrasonic waves downward in the ocean. When the sound waves reaches the ocean floor, they are reflected back to the ship . The time it takes for the signal to return is used to calculate the depth of submerged ship in the ocean.

Solution 21:
High Power, High Energy and good directionality are the properties of ultrasonic sounds which makes them useful.

Solution 22:

  • 10 Hz – Infrasonic sound.
  • 200 Hz – audible sound.
  • 2000 Hz – Audible sound.
  • 45 KHz – Ultrasonic sound

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Frank ICSE Solutions for Class 9 Physics – Sound: Production and Propagation of Sound

Frank ICSE Solutions for Class 9 Physics – Sound: Production and Propagation of Sound

PAGE NO: 278
Solution 1:
Yes, Sound is form of energy.

Solution 2:
Sound is produced by the vibrating objects.

Solution 3:
No, sound cannot travel through vacuum.

Solution 4:
Yes, sound can propagate through solids and liquids.

Solution 5:
No, sound cannot be produced in vacuum. It needs a material medium.

Solution 6:
Speed of sound depends on the density, pressure, temperature, humidity and Wind.

Solution 7:
330m/s is the value of speed in air at N.T.P

Solution 8:
In water, speed of sound is 4.5 times more than that in air. And, in iron, the speed of sound is 15 times as fast in air.

Solution 9:
The speed of sound is more in the humid air as compared to dry air. Because, the air moisture decreases the density of air and speed of sound is inversely proportional to density of air. So, sound travels faster in humid air.

Solution 10:
Speed of sound does not depend on the amplitude and wavelength.

Solution 11:
The sound produced by the moving wheels of the train travels faster on the iron track than in the air. So, firstly sound produced because of railway track is heard and then heard in the air.

Solution 12:
The waves in the air causes sound . Through waves , energy get transferred from one place to another and hence the sound.

Solution 13:
The ratio of speed of light to the speed of sound is 9.1 x 105.

Solution 14:
Speed of sound in air is independent of variation of pressure.

Solution 15:
The speed of sound in air increases with increase in temperature because with increase in temperature, the density of air gases decreases and speed of air is inversely proportional to density of air.

Solution 16:
The diver will hear the sound first because the sound travels faster in water than in air.

Solution 17:
The simple experiment that a person can do to calculate the speed of sound in air is that a person stands at a known distance (d meter) from the cliff and fires a pistol and simultaneously start the stop watch. He stops the stop-watch as soon as he hears a echo. The distance travelled by the sound during the time (t) seconds is 2d.
So, speed of sound = distance travelled / time taken = 2d/t

Solution 18:

  • Moisture in Air: The speed of sound increase with increase in humidity because the moisture in air decrease the density of air and speed of air is inversely proportional to density of air. Hence , the sound travels faster in moist air.
  • Pressure in air: Speed of sound is independent of the air pressure.
  • The speed of sound increases with the increase in temperature of the gas.

Solution 19:
The distance of flash from the observer = speed in air x time taken for the first sound to reach 330 x 6 = 1980m

Solution 20:
Distance between boys = speed of sound x time taken to reach sound = 330 x 2.5 = 825m

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Frank ICSE Solutions for Class 9 Biology – Respiratory System

Frank ICSE Solutions for Class 9 Biology – Respiratory System

PAGE NO:176

Solution 1:
Respiration: It is a process of release of energy from food substances such as glucose and fats under the control of enzymes, to carry out life processes, by the living organisms.
Respiration is essential for life as energy produced during this process is utilized by the organisms to carry out various biological activities.

Solution 2:
Structure of nasal chamber:
The nasal chamber is divided into left and right chambers by nasal septum. Each chamber is divided into three regions –

  1. Vestibule: It is the anterior most part of nasal chambers bearing hairs which filters the dust particles.
  2. Respiratory region: It is rich in mucous glands and marked by nasal turbinates which traps the dust and humidify the air.
  3. Olfactory chamber: It is lined by olfactory epithelium which sense the smell.

Solution 3:
Turbinates: The respiratory region of nasal chamber is marked by three nasal turbinates.These are Ethmoturbinate, nasoturbinate and maxilloturbinates.
Function of turbinates: It increases the surface area, so that dust particles can be removed and air become humidified.

Solution 4:
Adam’s apple : It is a prominent elevation formed by the laminae of thyroid cartilage. It is more pronounced in male than female.

Solution 5:
Frank ICSE Solutions for Class 9 Biology - Respiratory System 1

Solution 6:
The function of lecithin film in the lungs is to decrease the surface tension and keeps the alveoli open.

Solution 7:
Frank ICSE Solutions for Class 9 Biology - Respiratory System 2

Solution 8:
Breathing: It is the physical process of taking in oxygen and giving out carbon dioxide.
The function of diaphragm: It helps in breathing by contracting and relaxing thereby increase and decrease the volume of thoracic cavity. During inspiration diaphragm flattens while during expiration it becomes dome – shaped

Solution 9:

  1. Cough Reflex: It is a type of reflex whose stimulus is any foreign particle which results from deep inspiration followed by strong expiration that forcefully expel the air through the mouth.
  2.  Sneeze Reflex: It is a type of reflex whose stimulus is in the nasal passage which causes spasmodic contraction of expiratory muscles that forecefully expel the air through the nasal passage.
  3.  Eupnea: Eupnea is a normal breathing.
  4.  Dyspnea: A condition in which breathing is painful.
  5. Apnea: A condition in which no breathing takes place.

Solution 10:
Internal respiration: It is the transport of oxygen in the blood from the lungs to the cells and the transport of carbon dioxide from the tissue cells into the blood and to the lungs.

Solution 11:
Respiratory quotient (RQ): It is the ratio of CO2 output to O2 uptake. It is denoted by R.
R = Rate of CO2 output / Rate of O2 uptake
RQ for carbohydrate = 1.00
RQ for fat = 0.70
RQ for protein = 0.85

Solution 12:
(i) Vestibule
(ii) Larynx
(iii) Alveoli
(iv) Lecithin
(v) Hyperpnea
(vi) Dyspnea
(vii) Apnea
(viii) Hypopnea
(ix) Thoracic cavity

Solution 13:
(i) Pleura
(ii) Eupnea
(iii) 500 cc
(iv) 0.70
(v) 38 ATP

Solution 14:

  1.  Larynx = To produce voice
  2. Alveoli = To increase the surface area for exchange of gases.
  3. Conchae = It is also called turbinate and its function is to increase the surface area so that the dust particles can be removed and air become humidified.
  4. Epiglottis = It closes the glottis during swallowing of food.
  5. Lecithin covering = It lowers the surface tension and keeps the alveoli open.
  6. Cartilaginous rings = It prevents the collapsing of trachea.

Solution 15:

  1.  Alveoli – Gaseous exchange
  2. Larynx – Sound production
  3. Thoracic cage – Breathing

PAGE NO:177

Solution 16:
Frank ICSE Solutions for Class 9 Biology - Respiratory System 3

Solution 17:
(i)(b) Pleural membrane
(ii)(b) Alveoli
(iii)(d) All the above
(iv)(d) shows no change
(v)(d) 3000 – 4500 ml
(vi)(d) 158 and 116 mm Hg

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Frank ICSE Solutions for Class 9 Biology – Structure and Function of Skin

Frank ICSE Solutions for Class 9 Biology – Structure and Function of Skin

PAGE NO:169

Solution 1:
(a) Stratum corneum, transitional region, stratum germinativum
(b) Stratum germinativum
(c) Stratum corneum
(d) Dermis
(e) Sweat gland / sudoriferous gland
(f) Milk glands/ mammary glands
(g) Wax gland
(h) Epidermis
(i) Melanin

Solution 2:
(a) soles
(b) epidermis and dermis
(c) stratum corneum
(d) keratin
(e) mesoderm
(f) loose connective tissue
(g) sweat gland

Solution 3:
(a) True
(b) True
(c) True
(d) True
(e) False
(f) False

Solution 4:
(i) (a) stratum Malpighi
(ii) (d) palm
(iii) (b) stratum corneum
(iv) (b) dermis
(v) (b) dermis
(vi) (a) sweat gland
(vii) (c) constrict and the sweat glands are inactive

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