Theory of machines MCQs Archives

431. In the below figure, PC is the connecting rod and OC is the crank making an angle θ with the line of stroke PO and rotates with uniform angular velocity at ω rad/s. The Klien’s acceleration diagram for determining the acceleration of the piston P is shown by quadrilateral C Q NO. The acceleration of the piston P with respect to the crankpin C is given by

ω2 x NO

ω2 x CO

ω2 x CN

ω2 x QN

✅ The correct answer is option C.

432. Effort of a governor is the

mean force exerted at the sleeve for a given percentage change of speed

workdone at the sleeve for maximum equilibrium speed

mean force exerted at the sleeve for maximum equilibrium speed

none of the above

✅ The correct answer is option A.

433. The equivalent length of a simple pendulum depends upon the distance between the point of suspension and the centre of gravity.

TRUE

FALSE

✅ The correct answer is option A.

434. The component of the acceleration, parallel to the velocity of the particle, at the given instant is called

radial component

tangential component

coriolis component

none of these

✅ The correct answer is option B.

435. A body in motion will be subjected to coriolis acceleration when that body is

in plane rotation with variable velocity

in plane translation with variable velocity

in plane motion which is a resultant of plane translation and rotation

restrained to rotate w

✅ The correct answer is option D.

436. The contact ratio for gears is

zero

less than one

greater than one

infinity

✅ The correct answer is option C.

437. Pitch point of a cam is

a point on the pitch curve having minimum pressure angle

a point on the pitch curve having maximum pressure angle

any point on the pitch curve

any point on the pitch

✅ The correct answer is option B.

438. In a force-closed pair, the two elements of a pair are not held together mechanically.

Agree

Disagree

✅ The correct answer is option B.

439. The acceleration of piston in a reciprocating steam engine is given by (where ω = Angular velocity of crank, r = Radius of crank pin circle, θ = Angle turned by crank from inner dead centre, and n = Ratio of length of connecting rod to the radius of crank)

✅ The correct answer is option D.

440. In a steam engine, the earlier cut-off with a simple slide valve may be obtained by increasing the steam lap and the angle of advance of the eccentric but keeping constant the travel and lead of the valve, This method will

cause withdrawing or throttling of steam

reduce length of effective stroke of piston

reduce maximum opening of port to steam

all of these

✅ The correct answer is option C.