McqMate
| 101. |
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 |
| Answer» D. self-energized brake | |
| 102. |
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 |
| Answer» B. is increased | |
| 103. |
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 |
| Answer» C. less | |
| 104. |
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 |
| Answer» A. brake is equally effective in both the directions | |
| 105. |
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 |
| Answer» C. brake is more effective in clockwise directions | |
| 106. |
Refer fig.3 Pivot point O3, force at A vertically up and if µ.d ≥ b then____. |
| A. | the brake is self-locking in clockwise direction |
| B. | the brake is self-locking in counter-clockwise direction |
| C. | the brake is self-locking in both the direction |
| D. | the brake is not self-locking in any direction |
| Answer» B. the brake is self-locking in counter-clockwise direction | |
| 107. |
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. |
| Answer» B. o2 | |
| 108. |
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) |
| Answer» C. a<b | |
| 109. |
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 |
| Answer» D. all the above statements are correct | |
| 110. |
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 |
| Answer» D. all the above statements are correct | |
| 111. |
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 |
| Answer» A. more | |
| 112. |
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 |
| Answer» C. remains same irrespective of the weight of vehicle | |
| 113. |
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 _______ |
| A. | the stopping distance remains same |
| B. | the stopping distance increases by 50% |
| C. | the stopping distance decrease by 50% |
| D. | the stopping distance cannot be determined |
| Answer» C. the stopping distance decrease by 50% | |
| 114. |
For same μr and all wheels are impending slip, stopping distance for four wheel vehicle is _____ |
| A. | directly proportional to the velocity of vehicle |
| B. | directly proportional to square of the velocity of the vehicle |
| C. | directly proportional to weight of vehicle |
| D. | none of the above |
| Answer» B. directly proportional to square of the velocity of the vehicle | |
| 115. |
The stopping distance for four wheel vehicle is______ |
| A. | unaltered by increase for four wheel vehicle |
| B. | decrease with increase of μr |
| C. | directly proportional to square of velocity of vehicle |
| D. | all the above |
| Answer» D. all the above | |
| 116. |
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 |
| Answer» C. 44.36 kw | |
| 117. |
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_____ |
| A. | 0.2 |
| B. | 0.25 |
| C. | 0.3 |
| D. | 0.35 |
| Answer» D. 0.35 | |
| 118. |
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. |
| A. | 378.99 n |
| B. | 420.99 n |
| C. | 435.45 n |
| D. | 450.38 n |
| Answer» B. 420.99 n | |
| 119. |
For above question determine the required force 'P' to be applied when the rotation of drum is anticlockwise. |
| A. | 378.99 n |
| B. | 420.99 n |
| C. | 435.45 n |
| D. | 450.38 n |
| Answer» A. 378.99 n | |
| 120. |
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. |
| A. | 24.58 |
| B. | 25.58 |
| C. | 23.79 |
| D. | 35.48 |
| Answer» B. 25.58 | |
| 121. |
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 |
| A. | 102.99 n |
| B. | 105.24 n |
| C. | 103.26 n |
| D. | 195.38 n |
| Answer» C. 103.26 n | |
| 122. |
A dynamometer is a device used for measuring |
| A. | power developed by a machine |
| B. | torque developed by a machine |
| C. | power absorbed by a machine |
| D. | all the above |
| Answer» D. all the above | |
| 123. |
Dynamometer is a device for measuring ____ |
| A. | torque exerted by the machine |
| B. | power developed by the machine |
| C. | power absorbed by the machine |
| D. | all of the above |
| Answer» D. all of the above | |
| 124. |
Which of the following is classified a absorption type of dynamometer? |
| A. | prony brake dynamometer |
| B. | rope brake dynamometer |
| C. | hydraulic dynamometer |
| D. | all of the above |
| Answer» D. all of the above | |
| 125. |
Which of the following is classified as transmission type of dynamometer? |
| A. | prony brake dynamometer |
| B. | rope brake dynamometer |
| C. | hydraulic dynamometer |
| D. | epicyclic dynamometer |
| Answer» D. epicyclic dynamometer | |
| 126. |
Which of the following is an absorption type dynamometer? |
| A. | prony brake dynamometer |
| B. | rope brake dynamometer |
| C. | epicyclic-train dynamometer |
| D. | both a and b |
| Answer» D. both a and b | |
| 127. |
An example of an absorption type dynamometer is ___ |
| A. | prony brake dynamometer |
| B. | epicyclic train dynamometer |
| C. | torsion dynamometer |
| D. | belt transmission dynamometer |
| Answer» A. prony brake dynamometer | |
| 128. |
An example of a transmission dynamometer is______ |
| A. | prony brake dynamometer |
| B. | rope brake dynamometer |
| C. | froude dynamometer |
| D. | torsion dynamometer |
| Answer» D. torsion dynamometer | |
| 129. |
Which of the following is classified as absorption dynamometer? |
| A. | prony brake dynamometer |
| B. | rope brake dynamometer |
| C. | froude\s hydraulic dynamometer |
| D. | all of the above |
| Answer» C. froude\s hydraulic dynamometer | |
| 130. |
Which of the following is classified as transmission dynamometer? |
| A. | torsion dynamometer |
| B. | froude\s hydraulic dynamometer |
| C. | belt dynamometer or tathan dynamometer |
| D. | prony brake dynamometer |
| Answer» C. belt dynamometer or tathan dynamometer | |
| 131. |
In case of dynamometer function of counter weight is to _____ |
| A. | balance the brake when unloaded |
| B. | adjust pressure on pulley to control speed |
| C. | prevent rotation of block due to fraction between block and pulley |
| D. | to clamp the blocks |
| Answer» A. balance the brake when unloaded | |
| 132. |
Cooling water is used in________ |
| A. | prony brake dynamometer |
| B. | epicyclic gear train dynamometer |
| C. | torsion dynamometer |
| D. | rope brake dynamometer |
| Answer» D. rope brake dynamometer | |
| 133. |
Tathem dynamometer is name given to______ |
| A. | rope brake dynamometer |
| B. | belt transmission dynamometer |
| C. | absorption dynamometer |
| D. | epicyclic train dynamometer |
| Answer» B. belt transmission dynamometer | |
| 134. |
In case of Glibson flash light torsion dynamometer angle of twist can be measured up to _______ |
| A. | 1/20th of degree |
| B. | 1/10th of degree |
| C. | 1/70th of degree |
| D. | 1/100th of degree |
| Answer» D. 1/100th of degree | |
| 135. |
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. |
| A. | 3.91 kw |
| B. | 2.90 kw |
| C. | 4.90 kw |
| D. | 3.80 kw |
| Answer» A. 3.91 kw | |
| 136. |
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 |
| A. | 68.22 kw |
| B. | 67.22 kw |
| C. | 65.22 kw |
| D. | 66.32 kw |
| Answer» B. 67.22 kw | |
| 137. |
The uniform Pressure conditions are used_____. |
| A. | for safe design of clutches |
| B. | for maximum power to be transmitted |
| C. | for safe design bearing |
| D. | for the frictional torque |
| Answer» C. for safe design bearing | |
| 138. |
For safe design of brakes, we assume____. |
| A. | uniform pressure conditions |
| B. | uniform wear condition |
| C. | neither uniform pressure nor uniform wear |
| D. | all of the above |
| Answer» A. uniform pressure conditions | |
| 139. |
According to uniform wear theory____. Where,w=Angular velocity of shaft, r=radius of shaft, W=Axial lead on shaft |
| A. | pw=constant |
| B. | pr=constant |
| C. | pt=constant |
| D. | pw=constant |
| Answer» B. pr=constant | |
| 140. |
The uniform wear condition are used__________ |
| A. | for maximum power to be transmitted |
| B. | for safe design of clutches |
| C. | for safe design of bearing |
| D. | for overcoming the frictional torque |
| Answer» B. for safe design of clutches | |
| 141. |
According to uniform wear theory____. Where, w=Angular velocity of shaft, r=radius of shaft, W=Axial lead on shaft |
| A. | pw=constant |
| B. | pr=constant |
| C. | pt=constant |
| D. | pw=constant |
| Answer» B. pr=constant | |
| 142. |
The ratio of friction torque for uniform pressure to uniform were for the same dimensions and load is _____________. |
| A. | >1 |
| B. | =1 |
| C. | <1 |
| D. | =1/2 |
| Answer» A. >1 | |
| 143. |
Torque required to overcome the friction between shaft and bearing surface in case of multiple flat collar bearing is ___________. |
| A. | independent of no\s of collars |
| B. | dependent of radius of collars |
| C. | dependent of no\s of collars |
| D. | none of the above |
| Answer» A. independent of no\s of collars | |
| 144. |
According to uniform were theory frictional torque transmitted by conical pivot bearing is ________. |
| A. | 2/3 (μ w r cosec α) |
| B. | 1/2 (μ w r cosec α) |
| C. | 1/2 (μ w r cos α) |
| D. | μ w r cosec α |
| Answer» B. 1/2 (μ w r cosec α) | |
| 145. |
Frictional torque as per uniform were theory is __________. |
| A. | μp (ro+/ri) |
| B. | ½ μp (ro+/ri) |
| C. | ½ μp [(ro³+/ri³)/(ro²+/ri²)] |
| D. | μp(ro³-/ri³)/2 (ro²-/ri²) |
| Answer» C. ½ μp [(ro³+/ri³)/(ro²+/ri²)] | |
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