McqMate
| 1. |
The uniform wear conditions are used_____. |
| A. | for maximum power to be transmitted |
| B. | for safe design of clutches |
| C. | for safe design bearing |
| D. | for overcoming the frictional torque |
| Answer» B. for safe design of clutches | |
| 2. |
The uniform Pressure conditions are used_____. |
| A. | for maximum power to be transmitted |
| B. | for safe design of clutches |
| C. | for safe design bearing |
| D. | for overcoming the frictional torque |
| Answer» C. for safe design bearing | |
| 3. |
For safe design of bearing, we assume____. |
| A. | maximum power to be transmitted |
| B. | safe design of clutches |
| C. | safe design bearing |
| D. | overcoming the frictional torque |
| Answer» A. maximum power to be transmitted | |
| 4. |
For safe design of clutches, we assume____. |
| A. | uniform pressure conditions |
| B. | uniform wear condition |
| C. | neither uniform pressure nor uniform wear |
| D. | all of the above |
| Answer» B. uniform wear condition | |
| 5. |
According to uniform wear theory____. Where ,w=Angular velocity of shaft, r=radius of shaft, W=Axial lead on shaft |
| A. | p.w=constant |
| B. | p.r=constant |
| C. | p.w=constant |
| D. | p.t=constant |
| Answer» B. p.r=constant | |
| 6. |
In case of foot step bearing, the frictional force under the conditions of uniform pressure may be assumed to be acting at____. |
| A. | r |
| B. | (1/2).r |
| C. | (3/2).r |
| D. | (2/3)r |
| Answer» D. (2/3)r | |
| 7. |
In case of foot step bearing, the frictional force under the conditions of uniform wear may be assumed to be acting at____. |
| A. | r |
| B. | (1/2).r |
| C. | (3/2).r |
| D. | (2/3).r |
| Answer» B. (1/2).r | |
| 8. |
The ratio of friction torque for uniform pressure to uniform wear for the same dimensions and load is _______. |
| A. | >1 |
| B. | 1 |
| C. | <1 |
| D. | (1/2) |
| Answer» A. >1 | |
| 9. |
Torque required to overcome the friction between shaft and bearing surface in case of multiple flat collar bearing is ___________. |
| A. | independent on of collars |
| B. | dependent on radius of collar |
| C. | dependent of no of collars |
| D. | none of above |
| Answer» A. independent on of collars | |
| 10. |
In case of flat pivot bearing,the rubbing velocity is _________. |
| A. | maximum at the center of the contact area |
| B. | zero at the center and maximum at the outer radius |
| C. | uniform throughout the contact area |
| D. | zero at the outer radius |
| Answer» B. zero at the center and maximum at the outer radius | |
| 11. |
The rate of wearing in case of flat pivot bearing is ______. |
| A. | inversely proportional to the pressure intensity |
| B. | directly proportional to the rubbing velocity |
| C. | directly proportionl to the pressure intensity |
| D. | both (b) and (c ) |
| Answer» D. both (b) and (c ) | |
| 12. |
For calculating the friction power for bearing, the assumptions made in practice are_____. |
| A. | the rate of wearing at the surface is uniform |
| B. | the rubbing velocity is constant |
| C. | the pressure intensity is uniform |
| D. | (a) and (c ) only |
| Answer» D. (a) and (c ) only | |
| 13. |
In case of flat pivot bearing the frictional torque transmitted for uniform pressure as compared to the frictional torque transmitted for uniform wear_____. |
| A. | is more |
| B. | is less |
| C. | is constant |
| D. | may be more or less |
| Answer» A. is more | |
| 14. |
The ratio of friction torque transmitted for uniform pressure to frictional torque transmitted for uniform wear in case of flat pivot, is equal to_______. |
| A. | (1/3) |
| B. | (2/3) |
| C. | 1 |
| D. | (4/3) |
| Answer» D. (4/3) | |
| 15. |
When the axial load carried by the shaft in case of flat collar bearing, is large; a number of collars are provided on the shaft. This is done____. |
| A. | to reduce the frictional torque |
| B. | to increase the frictional torque |
| C. | to reduce the intensity of pressure |
| D. | to increse the intensity of pressure |
| Answer» C. to reduce the intensity of pressure | |
| 16. |
Choose the correct statement regarding the safe design of a bearing. |
| A. | when horse power lost in friction is to be determined, uniform rate of wear is assumed |
| B. | when horse power transmitted is to be determined, uniform pressure is assumed |
| C. | when horse power lost in friction is to be determined, uniform pressure is assumed and when horse power transmitted is to be determined, uniform wear is assumed |
| D. | none of the above |
| Answer» C. when horse power lost in friction is to be determined, uniform pressure is assumed and when horse power transmitted is to be determined, uniform wear is assumed | |
| 17. |
For uniform pressure the ratio of frictional torque for a flat collar bearing to the frictional torque for conical collar bearing is equal to____. Where ϴ=semi-angle of the cone |
| A. | 1.33 |
| B. | 1 |
| C. | sinϴ |
| D. | cosϴ |
| Answer» C. sinϴ | |
| 18. |
For uniform wear, the ratio of frictional torque for a flat collar bearing to the frictional torque for conical collar bearing is equal to____. Where ϴ=semi-angle of the cone |
| A. | 1.33 |
| B. | 1 |
| C. | sinϴ |
| D. | cosϴ |
| Answer» C. sinϴ | |
| 19. |
The ratio of frictional torque for a conical collar bearing to that for flat collar bearing is proportional to____. Where ϴ=semi-angle of the cone |
| A. | sinϴ |
| B. | cosϴ |
| C. | tanϴ |
| D. | 1/sinϴ |
| Answer» D. 1/sinϴ | |
| 20. |
For flat and conical pivots, the ratio of friction torque with uniform wear to friction torque with uniform pressure is ____. |
| A. | (2/3) |
| B. | (3/2) |
| C. | (4/3) |
| D. | (3/4) |
| Answer» D. (3/4) | |
| 21. |
The ratio of frictional torque produced for uniform wear to frictional torque produced for uniform pressure is ____. |
| A. | (3/4) |
| B. | (4/3) |
| C. | (2/3) |
| D. | 1 |
| Answer» A. (3/4) | |
| 22. |
The frictional torque for the same diameter in a conical bearing is ____. |
| A. | more |
| B. | less |
| C. | equal |
| D. | may be more or less |
| Answer» A. more | |
| 23. |
The frictional torque transmitted by a conical bearing is ____. |
| A. | less than that of flat collar bearing |
| B. | equal to that of flat collar bearing |
| C. | more than that of flat collar bearing |
| D. | none of the above |
| Answer» C. more than that of flat collar bearing | |
| 24. |
The frictional torque produced due to friction for same shaft diameter, in conical bearing is____. |
| A. | less than that for flat collar bearing |
| B. | equal to that for flat collar bearing |
| C. | more than that for flat collar bearing |
| D. | may be more or less depending upon cone angle |
| Answer» C. more than that for flat collar bearing | |
| 25. |
Choose the wrong statement |
| A. | the frictional torque transmitted by a shaft fitted with a large number of collars is the same as transmitted by a shaft with one collar |
| B. | the frictional force for uniform pressure, in case of a flat pivot bearing, can be assumed to be acting at a distance of two-thirds of the radius of the shaft from the axis of shaft. |
| C. | when horse power lost in friction is to be determined, uniform pressure is assumed for safe design of bearing |
| D. | the frictional force for uniform pressure, in case of a flat collar pivot bearing, can be assumed to be acting at a distance of half of the sum of internal and external radii of the shaft |
| Answer» D. the frictional force for uniform pressure, in case of a flat collar pivot bearing, can be assumed to be acting at a distance of half of the sum of internal and external radii of the shaft | |
| 26. |
The ratio of frictional torque produced for uniform wear to that for uniform pressure is ____. |
| A. | 1 |
| B. | (2/3) |
| C. | (4/3) |
| D. | (3/4) |
| Answer» D. (3/4) | |
| 27. |
In case of pivot bearing the rate of wear is _____. |
| A. | maximum at the center of the contact area |
| B. | zero at the center of contact |
| C. | uniform throughout the contact area |
| D. | zero at the maximum radius of the contact area |
| Answer» B. zero at the center of contact | |
| 28. |
The number of collars are provided to carry a fixed axial force in a flat collar bearing _______. |
| A. | to increase torque |
| B. | to decrease torque |
| C. | to decrease intensity of pressure |
| D. | to decrease intensity of pressure |
| Answer» C. to decrease intensity of pressure | |
| 29. |
In flat pivot bearing the total moment of friction force______. |
| A. | for uniform wear is greater than that for uniform pressure |
| B. | for uniform wear is less than that for uniform pressure |
| C. | for uniform wear is equal to that for uniform pressure |
| D. | for uniform wear may be more or less and cannot be predicted |
| Answer» B. for uniform wear is less than that for uniform pressure | |
| 30. |
To be safe side in the design, the unform pressure and uniform wear is assumed respectively_____. |
| A. | for power transmitted by friction and power lost due to friction |
| B. | for power lost due to friction and power transmitted by friction |
| C. | for torque transmitted by friction and friction torque overcome |
| D. | none of the above |
| Answer» B. for power lost due to friction and power transmitted by friction | |
| 31. |
Choose the correct statement for safe design. |
| A. | for power lost in friction uniform wear is assumed |
| B. | for power lost in friction uniform pressure is assumed |
| C. | for power transmitted due to friction uniform pressure is assumed |
| D. | for power transmitted due to friction or lost in friction uniform wear is assuned |
| Answer» B. for power lost in friction uniform pressure is assumed | |
| 32. |
Choose the correct statement for safe design. |
| A. | for power transmitted by friction uniform wear is assumed |
| B. | for power transmitted by friction uniform pressure is assumed |
| C. | for power lost in friction and power transmitted uniform wear is assumed |
| D. | power lost in friction and power transmitted uniform pressure is assuned |
| Answer» A. for power transmitted by friction uniform wear is assumed | |
| 33. |
The purpose of providing multiple collars on a flat collar pivot bearing is to ____. |
| A. | establish self sustaining bearing conditions |
| B. | increase the frictional resistance |
| C. | distribute the axial load because of limiting bearing pressure on bearing |
| D. | increase the power absorbed by the bearing |
| Answer» C. distribute the axial load because of limiting bearing pressure on bearing | |
| 34. |
In a multi-collared thrust bearing consisting of 'n' collars and subjected to axial load W, load sheared by each collar is _______. |
| A. | w |
| B. | w/n |
| C. | w/(n-1) |
| D. | none of these |
| Answer» B. w/n | |
| 35. |
A flat foot step bearing 20 cm in diameter supports a load of 2500 kgf. The shaft is running at 420 rpm and the co-efficient is 0.09. The frictional torque, for uniform pressure, will be equal to ___. |
| A. | 11.25 n-m |
| B. | 15 n-m |
| C. | 18.50 n-m |
| D. | 20.0 n-m |
| Answer» B. 15 n-m | |
| 36. |
A flat foot step bearing 20 cm in diameter supports a load of 2500 kgf. The shaft is running at 420 rpm and the co-efficient is 0.09. The frictional torque, for uniform wear, will be equal to ___. |
| A. | 11.25 n-m |
| B. | 15 n-m |
| C. | 18.50 n-m |
| D. | 20.0 n-m |
| Answer» A. 11.25 n-m | |
| 37. |
A flat foot step bearing 20 cm in diameter supports a load of 2500 kgf. The shaft is running at 420 rpm and the co-efficient is 0.09. The power lost in overcoming friction at the bearing, will be equal to ___. |
| A. | 650 watt |
| B. | 880 watt |
| C. | 659.7 watt |
| D. | 680.20 watt |
| Answer» C. 659.7 watt | |
| 38. |
flat foot step bearing 20 cm in diameter supports a load of 2500 kgf. The shaft is running at 420 rpm and the co-efficient is 0.09. The power transmitted by the friction between the surface, will be equal to ___. |
| A. | 493.875 watt |
| B. | 880 watt |
| C. | 659.7 watt |
| D. | 680.20 watt |
| Answer» A. 493.875 watt | |
| 39. |
A thrust bearing having collars of external and internal diameter as 40 cm and 20 cm respectively, carries an axial load of 3000 N. The co-efficient of friction is 0.09 and shaft runs at 420 rpm. The power lost in friction is to be determined. The corresponding value of friction torque would be ____. |
| A. | 40.5 n-m |
| B. | 42 n-m |
| C. | 45.0 n-m |
| D. | 48.5 n-m |
| Answer» B. 42 n-m | |
| 40. |
A thrust bearing having collars of external and internal diameter as 40 cm and 20 cm respectively, carries an axial load of 3000 N. The co-efficient of friction is 0.09 and shaft runs at 420 rpm. The power lost in friction would be equal to ____. |
| A. | 1.94 kw |
| B. | 1.84 kw |
| C. | 2 kw |
| D. | 2.5 kw |
| Answer» B. 1.84 kw | |
| 41. |
A flat footstep bearing 10 cm radius supports a load of 3 kN. The shaft runs at 600/π r.p.m. and co-efficient of friction is 0.1.The friction torque and frictional power in watts with uniform pressure are respectively. |
| A. | 10 n-m and 400 watts |
| B. | 20 n-m and 400 watts |
| C. | 30 n-m and 600 watts |
| D. | not possible to find for insufficient data |
| Answer» B. 20 n-m and 400 watts | |
| 42. |
A flat footstep bearing 10 cm radius supports a load of 3 kN. The shaft runs at 600/π r.p.m. and co-efficient of friction is 0.1. The friction torque and frictional power in watts with uniform wear are respectively. |
| A. | 30 n-m and 600 watt |
| B. | 15 n-m and 300 watts |
| C. | 15 n-m and 600 watts |
| D. | not possible to find for insufficient data |
| Answer» B. 15 n-m and 300 watts | |
| 43. |
A flat foot step bearing 225 mm in diameter supports a load of 7500 N. If the co-efficient of friction is 0.09 and the shaft rotates at 60 rpm, calculate the power lost in frictional torque and frictional power in watts with uniform pressure is ___. |
| A. | 50.62 n-m and 317.92 watt |
| B. | 60.62 n-m and 320.92 watt |
| C. | 57.68 n-m and 321.92 watt |
| D. | 55.50 n-m and 410.12 watt |
| Answer» A. 50.62 n-m and 317.92 watt | |
| 44. |
Following are the details pertaining to thrust bearing 1) External and internal dia of contacting surfaces-320 mm and 200 mm resp. 2) Axial load-80 kN 3)Pr. Intensity-350 kN/m2 4) shaft speed-400 rpm 5)coefficient of friction-0.06 Calculate power lost in overcoming friction. the frictional torque and power lost in frictional |
| A. | 600.35 nm and 26.60 kw |
| B. | 630.30 nm and 28.40 kw |
| C. | 635.08 nm and 26.60 kw |
| D. | 650.52 nm and 27.35 kw |
| Answer» C. 635.08 nm and 26.60 kw | |
| 45. |
A conical pivot supports a load of 20 kN, and its semicone angle is 41.81 degree. The friction coefficient is 0.06 and shaft runs at 200 rpm. The torque required to overcome friction and power lost in friction is |
| A. | 135.20 nm and 2.93 kw |
| B. | 125.40 nm and 2.93 kw |
| C. | 130.35 nm and 2.53 kw |
| D. | 135.36 nm and 2.83 kw |
| Answer» D. 135.36 nm and 2.83 kw | |
| 46. |
The clutch is a device used______ |
| A. | to absorb frictional torque |
| B. | to absorb frictional power |
| C. | to transmit power from on shaft to another |
| D. | all of the above |
| Answer» C. to transmit power from on shaft to another | |
| 47. |
Advantages of positive clutch is_____ |
| A. | they can be engaged at high speed |
| B. | they cause for high speed application |
| C. | shock and noise is there during engagement |
| D. | due to no slip between contact surfaces no heat is generated |
| Answer» D. due to no slip between contact surfaces no heat is generated | |
| 48. |
Disadvantages of positive clutch is______ |
| A. | they can be engaged at high speed |
| B. | they don’t provide positive engaged |
| C. | shock and noise is there during engagement |
| D. | due to no slip between contact surfaces no heat is generated |
| Answer» C. shock and noise is there during engagement | |
| 49. |
Torque transmitted by friction clutch_______ |
| A. | is more on the assumption of uniform pressure as compared to uniform wear |
| B. | is less on the assumption of uniform pressure as compared to uniform wear |
| C. | is same on the assumption of uniform pressure and uniform wear |
| D. | is more or less on the assumption of uniform pressure as compared to uniform wear depending upon material |
| Answer» A. is more on the assumption of uniform pressure as compared to uniform wear | |
| 50. |
For multiple plate clutch having 'n' is the effective number of surfaces for transmitting power then no. of plates are |
| A. | n+1 |
| B. | n-1 |
| C. | n |
| D. | n-2 |
| Answer» A. n+1 | |
| 51. |
Frictional torque transmission through plate clutch is equivalent to____ |
| A. | conical pivot bearing |
| B. | flat pivot bearing |
| C. | trapezoidal pivot bearing |
| D. | flat roller bearing |
| Answer» D. flat roller bearing | |
| 52. |
In case of cone clutch, power transmission is same as that of________ |
| A. | flat pivot bearing |
| B. | flat collar bearing |
| C. | trapezoidal pivot bearing |
| D. | conical pivot bearing |
| Answer» C. trapezoidal pivot bearing | |
| 53. |
Multiple clutch is kind of_________ |
| A. | positive clutch |
| B. | cone clutch |
| C. | centrifugal clutch |
| D. | disc clutch |
| Answer» D. disc clutch | |
| 54. |
Among which clutch heat dissipation is a serious problem? |
| A. | multiple clutch |
| B. | positive clutch |
| C. | cone clutch |
| D. | centrifugal clutch |
| Answer» A. multiple clutch | |
| 55. |
In case of clutch , uniform pressure theory is applicable for |
| A. | old clutch |
| B. | new clutch |
| C. | rusted clutch |
| D. | clutch made of hard material |
| Answer» B. new clutch | |
| 56. |
Centrifugal clutch are used in _____ |
| A. | truck |
| B. | racing car |
| C. | hack saw |
| D. | mopeds |
| Answer» D. mopeds | |
| 57. |
A friction clutch should be designed on the assumption of |
| A. | uniform wear |
| B. | uniform pressure |
| C. | constant friction |
| D. | any one |
| Answer» A. uniform wear | |
| 58. |
Considering the safe design, the friction clutch should be designed _______ |
| A. | assuming uniform pressure |
| B. | assuming uniform wear |
| C. | assuming any criteria, either uniform pressure or uniform wear |
| D. | assuming uniform pressure for high torque and uniform wear for low torque |
| Answer» B. assuming uniform wear | |
| 59. |
The equivalent coefficient of friction for a cone clutch is ____. |
| A. | µ sinα |
| B. | µ tanα |
| C. | µ/sinα |
| D. | µ/tanα |
| Answer» C. µ/sinα | |
| 60. |
Frictional torque transmission through multi plate clutch is equivalent to____. |
| A. | conical pivot bearing |
| B. | flat pivot bearing |
| C. | trapezoidal pivot bearing |
| D. | flat roller bearing |
| Answer» D. flat roller bearing | |
| 61. |
In case of multiplate clutch, power transmission is same as that of ______. |
| A. | flat pivot bearing |
| B. | flat pivot bearing |
| C. | trapezoidal pivot bearing |
| D. | conical pivot bearing |
| Answer» B. flat pivot bearing | |
| 62. |
Single plate clutch is a kind of _________. |
| A. | positive clutch |
| B. | cone clutch |
| C. | centrifugal clutch |
| D. | disc clutch |
| Answer» D. disc clutch | |
| 63. |
Which of the following is an example of friction clutch? |
| A. | disc clutch |
| B. | cone clutch |
| C. | centrifugal clutch |
| D. | all of the above |
| Answer» D. all of the above | |
| 64. |
The frictional torque transmitted by a disc clutch is same as that of _____. |
| A. | flat pivot bearing |
| B. | flat collar bearing |
| C. | conical pivot bearing |
| D. | trapezoidal pivot bearing |
| Answer» B. flat collar bearing | |
| 65. |
The frictional torque transmitted by a cone clutch is same as that of ____. |
| A. | flat pivot bearing |
| B. | flat collar bearing |
| C. | conical pivot bearing |
| D. | trapezoidal pivot bearing |
| Answer» D. trapezoidal pivot bearing | |
| 66. |
For safe design, a frictional clutch is designed assuming ____. |
| A. | uniform pressure theory |
| B. | uniform wear theory |
| C. | any one of the two |
| D. | none of the above |
| Answer» B. uniform wear theory | |
| 67. |
In multiple friction clutch, the number of active friction surfaces is ____. |
| A. | 2n |
| B. | n |
| C. | 2(n-1) |
| D. | n-1 |
| Answer» D. n-1 | |
| 68. |
Friction torque transmitted by a disc or plat clutch is same as that of ____. |
| A. | flat pivot bearing |
| B. | flat collar bearing |
| C. | conical pivot bearing |
| D. | truncated conical pivot bearing |
| Answer» B. flat collar bearing | |
| 69. |
For multiple plate friction clutch with n plates, the number of active surfaces n |
| A. | n |
| B. | n+1 |
| C. | n-1 |
| D. | n/2 |
| Answer» A. n | |
| 70. |
A single plate clutch is transmitting power, the inner and other radii of the plate are 10 cm and 22.5 cm respectively. Using the radius uniform wear theory, the maximum pressure intensity occurs at a radius of ____. |
| A. | 10 cm |
| B. | 15 cm |
| C. | 16.25 cm |
| D. | 22.5 cm |
| Answer» A. 10 cm | |
| 71. |
Torque transmitted by single plate clutch with axial spring load = 1 kN, and inner and outer radii of 10 cm and 15 cm and µ = 0.5 with assumption of uniform wear is ____. |
| A. | 250 n-m |
| B. | 125 n-m |
| C. | 62.5 n-m |
| D. | not possible to find with given data |
| Answer» C. 62.5 n-m | |
| 72. |
A multiple clutch with 5 plate transmits torque of 400 N-m. If µ = 0.5 and inner radius = 10 cm and outer radius = 15 cm and four spring expert-axial and load per spring is ___. |
| A. | 200 n |
| B. | 300 n |
| C. | 400 n |
| D. | 1280 n |
| Answer» C. 400 n | |
| 73. |
Determine the axial force required to engage a cone clutch transmitting 25 kW power at 750 rpm. Average friction diameter of the cone is 400 mm, semicone angle 10 degree and coefficient of friction 0.25. |
| A. | 325.30 nm and 1100.25 n |
| B. | 318.31 nm and 1105.47 n |
| C. | 320.25 nm and 1008.20 n |
| D. | 325.89 nm and 1120.30 n |
| Answer» B. 318.31 nm and 1105.47 n | |
| 74. |
Determine the axial force required to engage a cone clutch transmitting 25 kW power at 750 rpm. Average friction diameter of the cone is 400 mm, semicone angle 60 degree and coefficient of friction 0.25. |
| A. | 325.30 nm and 1100.25 n |
| B. | 318.31 nm and 1105.47 n |
| C. | 320.25 nm and 1008.20 n |
| D. | 325.89 nm and 1120.30 n |
| Answer» B. 318.31 nm and 1105.47 n | |
| 75. |
Can simple band brake be made of self-locking type? |
| A. | yes |
| B. | yes, but it will need many modifications |
| C. | yes, but with few limitations |
| D. | no |
| Answer» C. yes, but with few limitations | |
| 76. |
Material used for brake lining should not have ___. |
| A. | high heat dissipation capacity |
| B. | low heat resistance |
| C. | high strength |
| D. | high coefficient of friction |
| Answer» B. low heat resistance | |
| 77. |
pivoted block brake is a kind of ____. |
| A. | single block brake |
| B. | shoe brake |
| C. | differential expanding band brake |
| D. | internal expanding shoe brake |
| Answer» B. shoe brake | |
| 78. |
Which type of brakes are used in electric crane? |
| A. | internal expanding shoe brake |
| B. | differential band brake |
| C. | single block brake |
| D. | double bloke brake |
| Answer» D. double bloke brake | |
| 79. |
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. | a > b |
| B. | a = b |
| C. | a < b |
| D. | a = b2 |
| Answer» A. a > b | |
| 80. |
Brakes used in Railway engine are____. |
| A. | band brake |
| B. | internal expending brake |
| C. | shoe brake |
| D. | band and block brake |
| Answer» C. shoe brake | |
| 81. |
The brake commonly used in motor cars ____. |
| A. | shoe brake |
| B. | band brake |
| C. | band and block brake |
| D. | internal expanding brake |
| Answer» D. internal expanding brake | |
| 82. |
When will the distance travelled by 4-wheel be less after braking? |
| A. | applied to rear wheel |
| B. | when brakes applied to front wheel |
| C. | when brakes applied to all 4-wheels |
| D. | when brakes applied to rear wheel gradually |
| Answer» C. when brakes applied to all 4-wheels | |
| 83. |
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 |
| Answer» B. frictional torque opposes the applied torque | |
| 84. |
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 |
| Answer» C. act in downward direction | |
| 85. |
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 |
| Answer» A. be zero | |
| 86. |
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 |
| Answer» B. minimum | |
| 87. |
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 © |
| Answer» D. (a) and © | |
| 88. |
Brakes commonly used in trains are _____brakes. |
| A. | band |
| B. | shoe |
| C. | band and block |
| D. | internal expanding brake |
| Answer» B. shoe | |
| 89. |
In a self locking brake, the force required to apply the brake is_____. |
| A. | minimum |
| B. | zero |
| C. | maximum |
| D. | none of the above |
| Answer» B. zero | |
| 90. |
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 © |
| Answer» C. self-energizing | |
| 91. |
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 |
| Answer» A. leading shoe | |
| 92. |
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 |
| Answer» D. all of the above | |
| 93. |
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 |
| Answer» D. an internally expanding shoe brake | |
| 94. |
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 |
| Answer» D. same as © but effort is applied at end so as to over this end towards the drum | |
| 95. |
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 |
| Answer» A. a>b and p acts downwards | |
| 96. |
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 |
| Answer» D. drum rotates ccw and p acts downwards | |
| 97. |
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 |
| Answer» A. simple band brake | |
| 98. |
A short shoe brake has angle of contact less than____degree. |
| A. | 60 |
| B. | 120 |
| C. | 45 |
| D. | 90 |
| Answer» C. 45 | |
| 99. |
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 |
| Answer» A. less than 45 degree | |
| 100. |
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 |
| Answer» C. less than 1 | |
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