{"id":153968,"date":"2024-01-09T18:45:34","date_gmt":"2024-01-09T13:15:34","guid":{"rendered":"https:\/\/icsesolutions.com\/?p=153968"},"modified":"2024-01-10T10:20:30","modified_gmt":"2024-01-10T04:50:30","slug":"living-science-physics-class-6-icse-solutions-chapter-7","status":"publish","type":"post","link":"https:\/\/icsesolutions.com\/living-science-physics-class-6-icse-solutions-chapter-7\/","title":{"rendered":"Living Science Physics Class 6 ICSE Solutions Chapter 7 Simple Machine"},"content":{"rendered":"

ICSE Living Science Physics for Class 6 Solutions Chapter 7 Simple Machine<\/h2>\n

Check Your Progress (Page 78)<\/span><\/p>\n

Answer the following.<\/p>\n

Question 1.
\nWhat is a machine ?
\nAnswer;
\nTools and objects that help us to perform the same amount of work with much less effort than if we did the work manually, are called machines. Example : lever, hammer, knife, etc.<\/p>\n

Question 2.
\nWhat do you understand by a complex machine ?
\nAnswer:
\nMachines such as sewing machines or cars that have more than one moving part are called complex machines.<\/p>\n

Question 3.
\nName the simplest of all types of machines.
\nAnswer:
\nLever<\/p>\n

Question 4.
\nState the principle of levers.
\nAnswer:
\nThe principle of a lever states that the product of the load and the load arm is always equal to the product of the effort and the effort arm.
\nLoad x Load arm = Effort x Effort arm
\n\"Living
\nThe above ratio is called the mechanical advantage of a lever.<\/p>\n

Question 5.
\nWhat is a Class I lever ?
\nAnswer:
\nIn Class I levers (also called levers of first order), the fulcrum lies between the load and the effort, i.e., the load and the effort are on the opposite sides of the fulcrum. Examples : See-saw, pairs of scissors, pliers, beam balance, etc.
\nThe mechanical advantage of a Class I lever is always greater than one. These levers act as force multipliers.
\n\"Living<\/p>\n

A. Tick the most appropriate answer.<\/span><\/p>\n

Question 1.
\nThe force applied on a machine to do work is called the
\na. load
\nb. effort
\nc. efficiency
\nd. fulcrum
\nAnswer:
\nb. effort<\/p>\n

Question 2.
\nIf the effort lies between the fulcrum and the load, then the lever belongs to which class ?
\na. Class I
\nb. Class II
\nc. Class III
\nd. Class IV
\nAnswer:
\nc. Class III<\/p>\n

Question 3.
\nWhich of the following is a Class II lever ?
\na. Pliers
\nb. A beam balance
\nc. A nut-cracker
\nd. A knife
\nAnswer:
\nc. A nut-cracker<\/p>\n

Question 4.
\nA pair of scissors is an example of a\/an
\na. wedge
\nb. lever
\nc. inclined plane
\nd. screw
\nAnswer:
\nb. lever<\/p>\n

Question 5.
\nThe mechanical advantage of an inclined plane is always
\na. greater than 1
\nb. less than 1
\nc. equal to 1
\nd. zero
\nAnswer:
\na. greater than 1<\/p>\n

Question 6.
\nThe effort required to lift a load of 800 N by using a lever having a mechanical advantage of 1.6 is
\na. 1080 N
\nb. 240 N
\nc. 720 N
\nd. 500 N
\nAnswer:
\nd. 500 N<\/p>\n

Question 7.
\nA machine made up of two or more sloping surface is known as .a
\na. wedge
\nb. screw
\nc. pulley
\nd. lever
\nAnswer:
\na. wedge<\/p>\n

Question 8.
\nThe useful work done by a machine is known as the
\na. input energy
\nb. output energy
\nc. efficiency
\nd. effort
\nAnswer:
\nb. output energy<\/p>\n

B. State if the following statements are true or false. Correct the statement if it is false.<\/span><\/p>\n

Question 1.
\nThere are four types of simple machines.
\nAnswer:
\nFalse. There are six types of simple machines.<\/p>\n

Question 2.
\nThe load and effort can act at a single point in a lever.
\nAnswer:
\nFalse. The load and effort cannot act at a single point in a lever.<\/p>\n

Question 3.
\nA screw is a special case of an inclined plane.
\nAnswer:
\nTrue<\/p>\n

Question 4.
\nThe effort required to insert a screw into wood is less than that needed to insert a nail into wood.
\nAnswer:
\nTrue<\/p>\n

Question 5.
\nA single movable pulley is a pulley that has its axis of rotation fixed.
\nAnswer:
\nFalse. A single fixed pulley is a pulley that has its axis of rotation fixed.<\/p>\n

Question 6.
\nA rotation spindle tap is an example of a wheel-and-axle arrangement.
\nAnswer:
\nTrue<\/p>\n

Question 7.
\nA sewing needle is a wedge type simple machine.
\nAnswer:
\nTrue<\/p>\n

Question 8.
\nWork done by a machine is always more than the work done on a machine.
\nAnswer:
\nFalse. Work done by a machine is always less than the work done on a machine.<\/p>\n

C. Answer the following in a word or two or in a sentence.<\/span><\/p>\n

Question 1.
\nGiven an example of a Class I lever. >
\nAnswer:
\nSee-saw, pair of scissors<\/p>\n

Question 2.
\nWhich type of machine is used to squeeze a lemon ?
\nAnswer:
\nClass II lever<\/p>\n

Question 3.
\nWrite the relationship between mechanical advantage, load and effort.
\nAnswer:
\nMechanical advantage (MA) = \"Living<\/p>\n

Question 4.
\nName the type of machine made by putting two inclined planes together.
\nAnswer:
\nWedge .<\/p>\n

Question 5.
\nGive one example of a machine used to multiply speed.
\nAnswer:
\nClass III lever (hockey stick, forceps)<\/p>\n

Question 6.
\nWrite the formula for calculating the efficiency of a machine.
\nAnswer:
\nEfficiency = \"Living
\nThe percentage value of efficiency of a machine is calculated as :
\nEfficiency = \"Living<\/p>\n

D. Answer the following in short.<\/span><\/p>\n

Question 1.
\nExplain the various functions that a machine can perform.
\nAnswer:
\nVarious functions that a machine can perform are :<\/p>\n