1
According to the law of conservation of energy,

Answer: All of the above

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Questions

2
For an object of mass 'm', falling freely from height 'h', under acceleration due to gravity 'g', If v is the velocity of the object at a given instant, then during the course of its fall, for all points, which of the expression given below is correct ?

Answer: mgh + 1/2 mv2 = Constant

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3
In Force vs Displacement graph, What does the area under the curve represents :

Answer: Work done

4
A vector quantity has both magnitude as well as direction, where as a scalar quantity has only magnitude and no direction. which of the given below is a scalar quantity?

Answer: Ingredients

6
A body is moving with velocity 4 m/s , possesses 56 Joules of Kinetic Energy. The momentum of body will be equal to

Answer: 28 kgms-1

7
In a construction site, a crane lifts 1000 kg of concrete mix to roof top at a height of 20 meters in 50 seconds. If the value of gravity 'g' due to earth is 10 m s-2, the power of elevator will be..

Answer: 4 KW

8
An object is thrown vertically upward and it reaches to a maximum height 'h' from the ground. During its flight, on reaching 3/4 of height H, it will acquire?

Answer: more potential and less kinetic energy

9
An object is subjected to free fall from height 'h' to ground. At mid point of its fall i.e. at 1/2 of height H, it will acquire?

Answer: same kinetic and potential energy

10
An object is displaced by 10 meters in the direction of applied force. If the applied force is 75 N, What is the work done by the force?

Answer: 750 joule

11
According to the law of conservation of energy, which of the statements given below is correct ?

Answer: The total energy before and after the transformation always remains constant.

12
When a body slides down on an inclined surface, which holds true ?

Answer: It has both kinetic and potential energy

13
In hydro electricity generation, water stored in a dam possesses:

Answer: potential energy

14
When a body falls freely towards the earth then the total energy

Answer: remains constant

16
When we stretch a rubber band, the Elastic Potential Energy of rubber band

Answer: increases

17
The person will have maximum Potential Energy, when ?

Answer: he is standing on the roof

18
A cyclist is moving at a speed of 5 m/s on leveled road. While going down the slop, his speed increases to 7 m/s. Here the nature of work done by gravitational force in increasing the speed of cyclist is an example of ?

Answer: positive work done

19
In first case, a force of 5 N is applied on a object for 6 minutes and displaces it by 10 meters. In second case, A force of 10 N is applied on the same object for 3 minutes and displaces it by 5 meters. In which case there is more work done?

Answer: In both cases, work done is same

20
As per the statement of Q.9, the amount of addition work done by the car, after applying the accelerator, is

Answer: 4 Mv2

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