Strength of Materials MCQs

31. On a ladder resting on smooth ground and leaning against vertical wall, the force of friction will be__________________?

A. towards the wall at its upper end

B. away from the wall at its upper end

C. upwards at its upper end

D. downwards at its upper end

✅ The correct answer is option C.

32. The maximum frictional force which comes into play when a body just begins to slide over another surface is called_____________________?

A. limiting friction

B. sliding friction

C. rolling friction

D. kinematic friction

✅ The correct answer is option A.

33. Forces are called coplanar when all of them acting on body lie in________________?

A. one point

B. one plane

C. different planes

D. perpendicular planes

✅ The correct answer is option B.

34. If n = number of members andy = number of joints, then for a perfect frame, n =_______________?

A. j-2

B.2j-l

C. 2/-3

D.3/-2

✅ The correct answer is option C.

35. The algebraic sum of moments of the forces forming couple about any point in their plane is________________?

A. equal to the moment of the couple

B. constant

C. both of above are correct

D. both of above are wrong

✅ The correct answer is option A.

36. In detennining stresses in frames by methods of sections, the frame is divided into two parts by an imaginary section drawn in such a way as not to cut more than___________________?

A. two members with unknown forces of the frame

B. three members with unknown forces of the frame

C. four members with unknown forces of the frame

D. three members with known forces of the frame

✅ The correct answer is option B.

37. The center of gravity of a uniform lamina lies at_______________?

A. the center of heavy portion

B. the bottom surface

C. the mid point of its axis

D. all of the above

✅ The correct answer is option C.

38. D’ Alembert’s principle is used for___________________?

A. reducing the problem of kinetics to equivalent statics problem

B. determining stresses in the truss

C. stability of floating bodies

D. designing safe structures

✅ The correct answer is option A.

39. A flywheel on a motor goes from rest to 1000 rpm in 6 sec. The number of revolutions made is nearly equal to______________?

A. 25

B. 50

C. 100

D. 250

✅ The correct answer is option B.

40. Center of percussion is______________?

A. the point of C.G.

B. the point of metacentre

C. the point of application of the resultant of all the forces tending to cause a body to rotate about a certain axis

D. point of suspension

✅ The correct answer is option C.