21. The principle of transmissibility of forces states that, when a force acts upon a body, its effect is
A. same at every point on its line of action
B. different at different points on its line of action
C. minimum, if it acts at the center of gravity of the body
D. maximum, if it acts at the center of gravity of the body
22. A differential pulley block has larger and smaller diameters of 100 mm and 80 mm respectively. Its velocity ratio is
23. If three forces acting at a point are represented in magnitude and direction by the three sides of a triangle, taken in order, then the forces are in equilibrium
24. Newton’s second law motion __________ a relation between force and mass of a moving body.
B. does not give
25. The periodic time of one oscillation for a simple pendulum is(where l = Length of the pendulum.)
26. The resultant of two forces P and Q acting at an angle θ is
27. Which of the following are vector quantities?
A. Linear displacement
B. Linear velocity
C. Linear acceleration
D. all of these
28. The maximum acceleration of a particle moving with simple harmonic motion is
29. A lift moves downwards with an acceleration of 9.8 m/s2. The pressure exerted by a man on the floor of the lift is zero.
30. Non-coplanar concurrent forces are those forces which
A. meet at one point, but their lines of action do not lie on the same plane
B. does not meet at one point and their lines of action do not lie on the same plane
C. meet at one point and their lines of action also lie on the same plane
D. does not meet at one point, but their lines of action lie on the same plane