Unit Test - 2
Chapters 9 - 12
Marks - 20
Q.1. A. Fill in the blanks with proper words from the bracket. -3
(Circular, against, linear, along, energy, force)
1. The capacity that an object have for doing work is called energy.
2. The kite looking for it`s pray flies with circular motion in the sky.
3. The force of friction is always acts against the motion.
B. Match the pairs. -5
Group `A` Answer Group `B`
1. Uranium (Atomic energy ) a. Magnetic force
2. Sunlight ( Heat energy) b. Gravitational force
3. Food ( Chemical energy) c. Frictional force
4. Applying breaks to a bicycle(Frictional force) d. Atomic energy
5. Weighing with a spring balance (Gravitational force ) e. Heat energy
f. Chemical energy
C. Identify the type of motion. -5
1. Movement of earth around the sun : Circular, periodic
2. movement of ceiling fan : Circular, oscillatory
3. A meteor falling from the sky : Linear
4. A rocket launched from the ground : Linear
5. A fish swimming in water : Random
6. the plucked string of a sitar : Oscillatory
D. Name the force acting in the following examples. - 2
1. An object falling from a tall building : Gravitational force
2. An aero-plane flying in the sky : Mechanical force, frictional force, gravitational force, muscular force.
3. Squeezing sugarcane juice with a squeezer : Mechanical force, muscular force, frictional force.
4. Winnowing food grains : Muscular force, gravitational force.
Q.2. A. Identify the types of lever according to the positions of effort, fulcrum and load. -3
S.N.
Left side
Centre
Right side
Type of lever
1
Effort
Fulcrum
Load
I
2
Effort
Load
Fulcrum
II
3
Fulcrum
Effort
Load
III
B. Answer the following questions. -2
1. What are the various forms of energy?
Answer: Mechanical energy, heat energy, light energy, sound energy, chemical energy, electrical energy are the various forms of energy.
2. What are the non-conventional energy resources?
Answer: Non-conventional energy resources are : solar energy, wind energy, tidal energy, hydel power, atomic energy, energy obtained from the oceanic waves.
3. In which form is energy stored in plant food?
Answer: The energy is stored in the form of starch. that is in the chemical form in the plant food.
4. What is meant by weight?
Answer: The gravitational force acting on an object is called the weight of that object.
B. Give reasons. (Any 1) -2
1. Machines are oiled from time to time.
Answer: If machines are not oiled, the frictional force may be created between the surfaces of the machine. If frictional force is more it will slow down the speed and efficiency of the machine. therefore, machines are oiled from time to time.
2. Powder is sprinkled on a carrom board.
Answer: If powder is not sprinkled on the surface of the carrom board, there would be more frictional force. this will hinder the play. therefore to have a smooth carrom board surface, powder is sprinkled on a carrom board.
3. Traveller`s bags have wheels.
Answer: If heavy bag is to be lifted, it will require more effort. Instead, drawing it on wheels become easier and efficient. It consumes lesser time and lesser energy to carry a bag. therefore the traveller`s bags have wheels.
