Top 150+ Solved Theory of Mechanics MCQ Questions Answer
Q. In block brake, the normal reaction and frictional force act at the mid-point of the block. This is true only if the angle of contact is ____
a. less than 45 degree
b. less than 60 degree
c. greater than 45 degree
d. greater than 60 degree
Q. In a block brake, when the fulcrum point is below the line of action of friction point, the ratio of effort required for clockwise and counter clockwise rotation is____.
a. equal to 1
b. greater than 1
c. less than 1
d. unpredictable
Q. When moment due to friction force aids in applying the brake, it is called____.
a. simple block brake
b. pivoted block brake
c. self-locking brake
d. self-energized brake
Q. In a simple band brake, when direction of rotation of drum is changed from counter clockwise direction, the braking torque____.
a. remains unchanged
b. is increased
c. is decreased
d. is unpredictable
Q. In a differential band brake, the effort required for clockwise rotation of drum compared to counterclockwise rotation is____.
a. greater
b. equal
c. less
d. unpredictable
Q. Refer fig.3 pivot point O2, force at A acting vertically up, then ____.
a. brake is equally effective in both the directions
b. brake is more effective in counter-clockwise directions
c. brake is more effective in clockwise directions
d. brake is not effective in any direction
Q. Refer fig.3 pivot point O1, force at B acting vertically up, then ____.
a. brake is equally effective in both the directions
b. brake is more effective in counter-clockwise directions
c. brake is more effective in clockwise directions
d. brake is not effective in any direction
Q. Refer fig.3, The best choice for this brake is to have pivot point at____.
a. o1
b. o2
c. o3
d. anywhere between o3 and a.
Q. Refer fig.4. It shows a band brake arrangements. The brake to work with force at A upwards and direction of drum clockwise____.
a. a=b
b. a>b
c. a<b
d. independent of ratio (a/b)
Q. Refer Fig. 5 Force downwards and direction counter clockwise________
a. system will work only if a is greater than b
b. system will not work if a is less than b
c. system will not work if a is equal to b
d. all the above statements are correct
Q. Refer Fig. 5 Force downwards and direction counter clockwise________
a. a/b=t1/t2 gives self-lock
b. a=0 the brake still works
c. b=0 the brake does not work
d. all the above statements are correct
Q. The stopping distance for a vehicle by applying brakes when all the four wheels are sliding as compared to when all the four wheels are at impending slide is______
a. more
b. less
c. same
d. not predictable
Q. For the same co-efficient of friction between the road and the tier and assuming all the wheels at impending slip the stopping distance of vehicle from specified velocity on applying brakes
a. increase with increase of the weight of vehicle
b. decrease with increase of the weight of vehicle
c. remains same irrespective of the weight of vehicle
d. is unpredictable
Q. Find the brake power of the engine running at 755 rpm. The length of lever from center of pulley is 1.43 m. The weight in pan is 40 kg.
a. 40 kw
b. 42.44 kw
c. 44.36 kw
d. 45.41 kw