391. At the nodal point in a shaft, the amplitude for torsional vibration will be
minimum
maximum
zero
infinity
✅ The correct answer is option C.
Theory of machines MCQs
392. In a pantograph, all the pairs are
turning pairs
sliding pairs
spherical pairs
self-closed pairs
✅ The correct answer is option A.
393. The fundamental equation for correct steering is (where φ and α = Angle through which the axis of the outer wheel and inner wheel turns respectively, c = Distance between the pivots of the front axles, and d = Wheel base)
sin φ + sin α =
cos φ – sin α =
cot φ – cot α =
tan φ + cot α =
✅ The correct answer is option C.
394. Which of the following is a spring controlled governor?
Hartnell governor
Hartung governor
Wilson-Hartnell governor
all of these
✅ The correct answer is option D.
395. The essential condition of placing the two masses, so that the system becomes dynamically equivalent, is (where l1 and l2 = Distance of two masses from the centre of gravity of the body, and kG = Radius of gyration of the body)
l1 = kG
l2 = kG
l1l2 = kG
l1l2 = kG2
✅ The correct answer is option D.
396. A simple spring-mass vibrating system has a natural frequency of fn. If the spring stiffness is halved and the mass is doubled, then the natural frequency will become
fn/2
2 fn
4 fn
8 fn
✅ The correct answer is option A.
397. Most of the engines, generally, do not require balancing of secondary forces and couples.
Right
Wrong
✅ The correct answer is option A.
399. In full depth involute system, the smallest number of teeth in a pinion which meshes with rack without interference is
12
16
25
32
✅ The correct answer is option D.
400. The size of cam depends upon
base circle
pitch circle
prime circle
pitch curve
✅ The correct answer is option A.