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This set of Theory of Mechanics Multiple Choice Questions & Answers (MCQs) focuses on Theory Of Mechanics Set 4
Q1 | Material used for brake lining should not have ___.
- high heat dissipation capacity
- low heat resistance
- high strength
- high coefficient of friction
Q2 | pivoted block brake is a kind of ____.
- single block brake
- shoe brake
- differential expanding band brake
- internal expanding shoe brake
Q3 | Which type of brakes are used in electric crane?
- internal expanding shoe brake
- differential band brake
- single block brake
- double bloke brake
Q4 | In a band brake 'a' is perpendicular distance between slack side and pivot point and 'b' is perpendicular distances between tight side and pivot point. If applied force is downwards then ___.
- a > b
- a = b
- a < b
- a = b2
Q5 | Brakes used in Railway engine are____.
- band brake
- internal expending brake
- shoe brake
- band and block brake
Q6 | The brake commonly used in motor cars ____.
- shoe brake
- band brake
- band and block brake
- internal expanding brake
Q7 | When will the distance travelled by 4-wheel be less after braking?
- applied to rear wheel
- when brakes applied to front wheel
- when brakes applied to all 4-wheels
- when brakes applied to rear wheel gradually
Q8 | Brakes are self energizing when____.
- frictional torque assists the applied torque
- frictional torque opposes the applied torque
- frictional torque vanishes
- none of the above
Q9 | 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____.
- be zero
- act in upward direction
- act in downward direction
- none of the above
Q10 | For the brake to be self locking, the force P at C as shown in fig.1 should____.
- be zero
- act in upward direction
- act in downward direction
- none of the above
Q11 | When brakes are applied to all the four wheels of a moving car before it is brought to rest, will be____.
- maximum
- minimum
- both (a) and (b)
- none of the above
Q12 | Which of the following brakes is commonly used in two wheelers?
- disc brake
- band brake
- internal expanding shoe brake
- (a) and ©
Q13 | Brakes commonly used in trains are _____brakes.
- band
- shoe
- band and block
- internal expanding brake
Q14 | In a self locking brake, the force required to apply the brake is_____.
- minimum
- zero
- maximum
- none of the above
Q15 | When the frictional force helps the applied force in applying the brake, the brake is____.
- self locking
- automatic
- self-energizing
- (a) and ©
Q16 | In an internal expanding shoe brake, more than 50% of the total braking torque is supplied by____.
- leading shoe
- trailing shoe
- any of the above
- none of these
Q17 | Tractive resistance during the propulsion of a wheeled vehicle depends on____.
- road resistance
- aerodynamic resistance b
- gradient resistance
- all of the above
Q18 | A motor car uses____.
- a band brake
- a band and block brake
- an external shoe brake
- an internally expanding shoe brake
Q19 | For a simple band brake to be effective____.
- tight side is connected to free end of lever and effort is applied at end so as to move this end away from drum
- same as (a) above but effort is so applied at end as to move this end towards the drum
- 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
- same as © but effort is applied at end so as to over this end towards the drum
Q20 | For ccw direction of drum rotation in fig.2 brake applied if ____.
- a>b and p acts downwards
- a
- a=b and p acts downwards
- a>b and p acts upwards
Q21 | The band brake in fig.2 will be self-energizing when____.
- drum rotates ccw and p acts upwards
- drum rotates ccw and p acts downwards
- drum rotates cw and p acts upwards
- drum rotates ccw and p acts downwards
Q22 | Self-locking is not possible in the case of____.
- simple band brake
- differential band brake
- simple block brake
- internal expanding brake
Q23 | A short shoe brake has angle of contact less than____degree.
- 60
- 120
- 45
- 90
Q24 | 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 ____
- less than 45 degree
- less than 60 degree
- greater than 45 degree
- greater than 60 degree
Q25 | 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____.
- equal to 1
- greater than 1
- less than 1
- unpredictable