11. The velocity ratio for the second system of pulleys is n.
A. True
B. False
12. The law of motion involved in the recoil of the gun is
A. Newton’s first law of motion
B. Newton’s second law of motion
C. Newton’s third law of motion
D. none of these
13. When a particle moves along a circular path, its acceleration has two components, one is normal component and the other is tangential component of acceleration.
A. True
B. False
14. A machine which is not capable of doing any work in the reversed direction, after the effort is removed, is called a reversible machine.
A. True
B. False
15. The range of projectile will be maximum for a given velocity of the projectile when the angle of projection (α) is
A. β/2
B. 30° + β/2
C. 45° + β/2
D. 60° + β/2
16. When two elastic bodies collide with each other,
A. the two bodies will momentarily come to rest after the collision
B. the two bodies tend to compress and deform at the surface of the contact
C. the two bodies begin to regain their original shape
D. all of the above
17. The centre of gravity of a triangle lies at a point where its medians intersect each other.
A. True
B. False
18. In order to double the period of simple pendulum, the length of the string should be
A. halved
B. doubled
C. quadrupled
19. The moment of inertia of a square of side an about its base is a4/ 3
A. True
B. False
20. If the number of pulleys in a system is equal to its velocity ratio, then it is a __________ system of pulleys
A. first
B. second
C. third