Theory of machines MCQs Archives

231. Which of the following is an example of sliding pair?

Piston and cylinder of a reciprocating steam engine

Shaft with collars at both ends fitted into a circular hole

Lead screw of a lathe with nut

Ball and a socket join

✅ The correct answer is option A.

232. In order to facilitate starting of locomotive in any position, the cranks of a locomotive with two cylinders, are placed at

45° to each other

90° to each other

120° to each other

180° to each other

✅ The correct answer is option B.

233. The sensitiveness of a governor depends upon the lift of the sleeve.

Right

Wrong

✅ The correct answer is option A.

234. In a locomotive, the resultant unbalanced force due to the two cylinders along the line of stroke, is known as

tractive force

swaying couple

hammer blow

none of these

✅ The correct answer is option A.

235. In considering friction of a V-thread, the virtual coefficient of friction (μ1) is given by

μ1 = μ sin β

μ1 = μ cos β

✅ The correct answer is option D.

236. The amplitude of vibration is always __________ the radius of the circle.

equal to

less than

greater than

✅ The correct answer is option A.

237. The pressure angle for involute gears depends upon the size of teeth.

Right

Wrong

✅ The correct answer is option B.

238. In order to give a complete secondary balance of a multi-cylinder in-line engine,

the algebraic sum of the secondary forces must be equal to zero

the algebraic sum of the couples about any point in the plane of the secondary forces must be equal to zero

both (a) and (b)

none of these

✅ The correct answer is option C.

239. In a disc clutch, if there are n1 number of discs on the driving shaft and n2 number of discs on the driven shaft, then the number of pairs of contact surfaces will be

n1 + n2

n1 + n2 + 1

n1 + n2 – 1

n1 + n2 – 2

✅ The correct answer is option C.

240. In a Hartnell governor, the lift of the sleeve is given by (where r1 and r2 = Max. and min. radii of rotation, x = Length of ball arm of the lever, and y = Length of sleeve arm of the lever)

(r1 + r2)

(r1 – r2)

✅ The correct answer is option C.