221. When two pulleys of different diameters are connected by means of an open belt, the angle of contact at the __________ pulley must be taken into consideration.
smaller
larger
✅ The correct answer is option A.
Theory of machines MCQs
222. The effect of swaying couple in a locomotive is resisted by the side pressure between the flanges of the tyres of the wheel and the inside of the rails.
Agree
Disagree
✅ The correct answer is option A.
223. The Klein’s diagram is used when
crank has uniform angular velocity
crank has non-uniform angular velocity
crank has uniform angular accleration
crank has non-uniform
✅ The correct answer is option A.
225. The centre of suspension and centre of percussion are not interchangeable.
Correct
Incorrect
✅ The correct answer is option B.
226. The mechanism in which two are turning pairs and two are sliding pairs, is called a
double slider crank chain
elliptical trammel
Scotch yoke mechanism
all of these
✅ The correct answer is option D.
227. The maximum efficiency of spiral gears is (where θ = Shaft angle, and φ = Friction angle)
✅ The correct answer is option C.
228. The primary unbalanced force is maximum __________ in one revolution of the crank.
twice
four times
eight times
sixteen times
✅ The correct answer is option A.
229. In a steam engine, the earlier cut-off with a simple slide valve may be obtained by increasing the angle of advance of the eccentric but reducing the throw of the eccentric and keeping the steam lap and exhaust lap constant. This method will cause withdrawing or throttling of steam.
Agree
Disagree
✅ The correct answer is option A.
230. Under logarithmic decrement, the amplitude of successive vibrations are
constant
in arithmetic progression
in geometric progression
in logarithmic progres
✅ The correct answer is option C.