Top 150+ Solved Theory of Mechanics MCQ Questions Answer
Q. Brakes are self energizing when____.
a. frictional torque assists the applied torque
b. frictional torque opposes the applied torque
c. frictional torque vanishes
d. none of the above
Q. In a differential band brake, as shown in fig.1the length OA is greater than OB. In order to apply the brake, the force at C should____.
a. be zero
b. act in upward direction
c. act in downward direction
d. none of the above
Q. For the brake to be self locking, the force P at C as shown in fig.1 should____.
a. be zero
b. act in upward direction
c. act in downward direction
d. none of the above
Q. When brakes are applied to all the four wheels of a moving car before it is brought to rest, will be____.
a. maximum
b. minimum
c. both (a) and (b)
d. none of the above
Q. Which of the following brakes is commonly used in two wheelers?
a. disc brake
b. band brake
c. internal expanding shoe brake
d. (a) and ©
Q. Brakes commonly used in trains are _____brakes.
a. band
b. shoe
c. band and block
d. internal expanding brake
Q. In a self locking brake, the force required to apply the brake is_____.
a. minimum
b. zero
c. maximum
d. none of the above
Q. When the frictional force helps the applied force in applying the brake, the brake is____.
a. self locking
b. automatic
c. self-energizing
d. (a) and ©
Q. In an internal expanding shoe brake, more than 50% of the total braking torque is supplied by____.
a. leading shoe
b. trailing shoe
c. any of the above
d. none of these
Q. Tractive resistance during the propulsion of a wheeled vehicle depends on____.
a. road resistance
b. aerodynamic resistance b
c. gradient resistance
d. all of the above
Q. A motor car uses____.
a. a band brake
b. a band and block brake
c. an external shoe brake
d. an internally expanding shoe brake
Q. For a simple band brake to be effective____.
a. tight side is connected to free end of lever and effort is applied at end so as to move this end away from drum
b. same as (a) above but effort is so applied at end as to move this end towards the drum
c. slack side is connected to the free end of the lever and the effort is applied at end so as to move it away from drum
d. same as © but effort is applied at end so as to over this end towards the drum
Q. For ccw direction of drum rotation in fig.2 brake applied if ____.
a. a>b and p acts downwards
b. a<b and p acts downwards
c. a=b and p acts downwards
d. a>b and p acts upwards
Q. The band brake in fig.2 will be self-energizing when____.
a. drum rotates ccw and p acts upwards
b. drum rotates ccw and p acts downwards
c. drum rotates cw and p acts upwards
d. drum rotates ccw and p acts downwards
Q. Self-locking is not possible in the case of____.
a. simple band brake
b. differential band brake
c. simple block brake
d. internal expanding brake