1. When moment due to friction force aids in applying the brake, it is called____.
Correct : D. self-energized brake
2. In a simple band brake, when direction of rotation of drum is changed from counter clockwise direction, the braking torque____.
Correct : B. is increased
3. In a differential band brake, the effort required for clockwise rotation of drum compared to counterclockwise rotation is____.
Correct : C. less
4. Refer fig.3 pivot point O2, force at A acting vertically up, then ____.
Correct : A. brake is equally effective in both the directions
5. Refer fig.3 pivot point O1, force at B acting vertically up, then ____.
Correct : C. brake is more effective in clockwise directions
6. Refer fig.3 Pivot point O3, force at A vertically up and if µ.d ≥ b then____.
Correct : B. the brake is self-locking in counter-clockwise direction
7. Refer fig.3, The best choice for this brake is to have pivot point at____.
Correct : B. o2
8. Refer fig.4. It shows a band brake arrangements. The brake to work with force at A upwards and direction of drum clockwise____.
Correct : C. a<b
9. Refer Fig. 5 Force downwards and direction counter clockwise________
Correct : D. all the above statements are correct
10. Refer Fig. 5 Force downwards and direction counter clockwise________
Correct : D. all the above statements are correct
11. 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______
Correct : A. more
12. 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
Correct : C. remains same irrespective of the weight of vehicle
13. A vehicle has weight W and co-efficient of tractive co-efficient μr. It is moving with velocity V when brakes are applied, and all the wheels are at impending slip. The stopping distance Is x. If weight is increased by 50% and μr decreased by 50% then _______
Correct : C. the stopping distance decrease by 50%
14. For same μr and all wheels are impending slip, stopping distance for four wheel vehicle is _____
Correct : B. directly proportional to square of the velocity of the vehicle
15. The stopping distance for four wheel vehicle is______
Correct : D. all the above
16. 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.
Correct : C. 44.36 kw
17. In a band brake the ratio of tight side band tension to the tension on the slack side is 3. If the angle of band on the drum is 1800 the coefficient of friction required between drum and band is_____
Correct : D. 0.35
18. A single block brake as shown in Fig.6 has a brake drum diameter of 1m and the angle of contact is 300. It takes 280 Nm torque at 300rpm. The coefficient of friction is 0.35. Determine the required force 'P' to be applied when the rotation of drum is clockwise.
Correct : B. 420.99 n
19. For above question determine the required force 'P' to be applied when the rotation of drum is anticlockwise.
Correct : A. 378.99 n
20. A bicycle and rider is mass 125 kg are travelling at speed of 10km/hr. The rider applies a break to the near wheel of 1 m diameter. How far the bicycle will travel before it comes to rest? The pressure applied to the brake is 120 N and μ = 0.05. Also find the number of revolutions made by bicycle before coming to rest.
Correct : B. 25.58
21. In a simple band brake applied to a shaft carrying a flywheel of mass 250kg and radius of gyration 350mm , one end of the band is attached to the fulcrum and the other at a distance 300 mm from the fulcrum. The angle embraced by the band is 2250 and the brake drum diameter is 220 mm coefficient of friction 0.25 and the shaft speed is 300 rpm clockwise. Determine the brake torque when a force of 150 N is applied
Correct : C. 103.26 n
22. A dynamometer is a device used for measuring
Correct : D. all the above
23. Dynamometer is a device for measuring ____
Correct : D. all of the above
24. Which of the following is classified a absorption type of dynamometer?
Correct : D. all of the above
25. Which of the following is classified as transmission type of dynamometer?
Correct : D. epicyclic dynamometer
26. Which of the following is an absorption type dynamometer?
Correct : D. both a and b
27. An example of an absorption type dynamometer is ___
Correct : A. prony brake dynamometer
28. An example of a transmission dynamometer is______
Correct : D. torsion dynamometer
29. Which of the following is classified as absorption dynamometer?
Correct : C. froude\s hydraulic dynamometer
30. Which of the following is classified as transmission dynamometer?
Correct : C. belt dynamometer or tathan dynamometer
31. In case of dynamometer function of counter weight is to _____
Correct : A. balance the brake when unloaded
32. Cooling water is used in________
Correct : D. rope brake dynamometer
33. Tathem dynamometer is name given to______
Correct : B. belt transmission dynamometer
34. In case of Glibson flash light torsion dynamometer angle of twist can be measured up to _______
Correct : D. 1/100th of degree
35. The following data refer to a laboratory experiment with rope brake____.Diameter of the flywheel=1m Diameter of the rope = 10mm , Dead weight on the brake = 50kg , Speed of the engine = 200rpm , Spring balance reading = 120N . Find brake power of the engine.
Correct : A. 3.91 kw
36. A torsion dynamometer is fitted on turbine shaft to measure the angle of twist. The shaft twist 1.60 for a length of 8 meters at 600 rpm. The diameter of shaft is 250 mm. Find the power transmitted by the turbine. Take G= 80 GPa
Correct : B. 67.22 kw
37. The uniform Pressure conditions are used_____.
Correct : C. for safe design bearing
38. For safe design of brakes, we assume____.
Correct : A. uniform pressure conditions
39. According to uniform wear theory____. Where,w=Angular velocity of shaft, r=radius of shaft, W=Axial lead on shaft
Correct : B. pr=constant
40. The uniform wear condition are used__________
Correct : B. for safe design of clutches
41. According to uniform wear theory____. Where, w=Angular velocity of shaft, r=radius of shaft, W=Axial lead on shaft
Correct : B. pr=constant
42. The ratio of friction torque for uniform pressure to uniform were for the same dimensions and load is _____________.
Correct : A. >1
43. Torque required to overcome the friction between shaft and bearing surface in case of multiple flat collar bearing is ___________.
Correct : A. independent of no\s of collars
44. According to uniform were theory frictional torque transmitted by conical pivot bearing is ________.
Correct : B. 1/2 (μ w r cosec α)
45. Frictional torque as per uniform were theory is __________.