Physics Chapter 2 Entry test MCQs
Topic 2
Work and Energy
1. A truck and a car are moving with equal velocity. On applying brakes, both will stop after a certain distance, then?
a. Truck will cover less distance before stopping
b. Car will cover less distance before stopping
c. Both will cover equal distance
d. None of the mentioned
2. What sort of energy does flying bird possess?
a. Elastic energy
b. Potential energy
c. Both potential and kinetic energy
d. Kinetic energy
3. When the velocity of an aero plane is doubled, the momentum————–.
a. Becomes zero
b. Remains unchanged
c. Increases uniformly
d. Is conserved
4. A machine gun fires 60 bullets per minute, with a velocity of 700m/s. If each bullet has a mass of 50g, find the power developed by the gun.
a. 122.5W
b. 1225W
c. 122W
d. 12250W
5. A bullet fired from a gun can pierce a target due to its———-.
a. Kinetic energy
b. Mechanical energy
c. Acceleration
d. Heat energy
6. Kinetic energy with any reference must be———–.
a. Negative
b. Zero
c. Either negative or positive
d. Positive
7. At what angle work done will be maximum?
a. 90°
b. 0°
c. 30°
d. 45°
8. Which one of the following is a greater work?
a. -100 J
b. +100 J
c. +200 J
d. -1000 J
9. The figure shows the force distance curve of a body moving along a straight line. The work done by the force:
a. 20 J
b. 10 J
c. 40 J
d. 30 J
10. Work done will be zero if angle between Force and displacement is:
a. 60°
b. 0°
c. 360°
d. 270°
11. A force 2i + j has moved its point of application from (2,3) to (6,5). What is work done?
a. +10
b. -10
c. +18
d. -18
12. At what angle the work done will be half of its maximum value
a. 450°
b. 0°
c. 60°
d. 30°
13. A man pushes a wall with 50 (N) and it displaces it zero (m), his work is
a. Positive
b. Negative
c. May all possible
d. No work
14. If a mass of 5 Kg is lifted upto 5m height, what will be the work done against the gravitational field.
a. 49 J
b. 245 J
c. 98 J
d. 25 J
15. A person walks 2 m with an acceleration of 5 ms-², holding an object of mass 2 kg. The net work done on the object is
a. 5J
b. 20 J
c. 0 J
d. 10 J
16. A force of 3i+2j+4k N gives displacement of 10m. The work done is
a. 32 J
b. 20 J
c. Zero
d. 26 J
17. A body travels displacement of 10 m by force of 5 N If work done is 25 J then angle between F and d is
a. 30°
b. 0°
c. 60°
d. 45°
18. A person holds a bucket of weight 60N. He walks 7 m along the horizontal path and then climbs up a vertical distance of 5 m. The work done by the gravity is:
a. 420 N-m
b. 300 N-m
c. 720 N-m
d. None of these
19. A force F acting on an object varies with distance x as shown in fig. The work done by the force in moving the object from x = 0 to x = 6 m is
a. 18J
b. 9J
c. 13.5J
d. 4.5J
20. If force and displacement of particle in direction of force are doubled. Work would be
a. Half
b. Double
c. 4 times
d. 1/4 times
21. A person is holding a bucket by applying a force of 10N. He moves a horizontal distance of 5m and then climbs up a vertical distance of 10m. Find the total work done by him?
a. 150J
b. 50J
c. 200J
d. 100J
22. A gardener pushes a lawn roller through a distance of 20m. If he applies a force of 20kg weight in a direction inclined at 60° to the ground, find the work done by him. (g = 9.8m/s2)
a. 1960J
b. 400J
c. 2514J
d. 250J
23. If velocity is double, then.
a. Momentum and K.E remain same
b. Momentum increase 4 times and K.E increases 2 times
c. Momentum increases 2 times and K.E increases 4 times
d. Momentum increases 2 times and K.E increase constant
24. What will be the ratio of kinetic energies of alpha particle and proton if their linear momentum will be same?
a. 1:4
b. 18:1
c. 104 : 1
d. 4:1
25. The Bodies of one kg and four kg have same kinetic energy. The ratio in their momenta will be
a. 1:16
b. 1:2
c. 1:1
d. 1:4