# Power Transmission Devices - Mechanical Engineering (MCQ) questions and answers

1)   Determine power rating of an electric motor if it runs at 1440 r.p.m and line shaft transmits torque of 75 Nm.  Assume Reduction ratio = 1.6

a. 10.36 kW
b. 11.3 kW
c. 7.068 kW
d. 9.12 kW
 Answer  Explanation ANSWER: 7.068 kW Explanation: No explanation is available for this question!

2)   Why is an idler gear used in gear trains?

a. To obtain minimum centre distance between driving and driven shaft
b. To have required direction of rotation
c. Both a. and b.
d. None of the above
 Answer  Explanation ANSWER: To have required direction of rotation Explanation: No explanation is available for this question!

3)   Which gears are used to connect two intersecting shaft axes?

a. Crossed helical gear
b. Worm and worm wheel
c. Bevel gears
d. All of the above
 Answer  Explanation ANSWER: Bevel gears Explanation: No explanation is available for this question!

4)   Determine torque transmitted on the pinion shaft if torque transmitted on gear shaft is 20 Nm.
Consider Gear ratio = 4

a. 8 Nm
b. 5 Nm
c. 80 Nm
d. 16 Nm
 Answer  Explanation ANSWER: 5 Nm Explanation: No explanation is available for this question!

5)   Which flat belt drive system has two pulleys mounted on driven shaft and one pulley on driving shaft?

a. Multiple belt drive
b. Cone pulley drive
c. Fast and loose pulley drive
d. None of the above
 Answer  Explanation ANSWER: Fast and loose pulley drive Explanation: No explanation is available for this question!

6)   Which of the following statements are false for belt drives?

1. Belt drive is used in applications having constant speed drive
2. Belt drives can be used at extremely high speeds
3. Belt drives have low power transmitting capacity
4. Belt drives need continuous lubrication

a. 1 and 2
b. 1, 2 and 3
c. 2, 3 and 4
d. 1, 2 and 4
 Answer  Explanation ANSWER: 1, 2 and 4 Explanation: No explanation is available for this question!

7)   In simple gear trains the direction of rotation of driven gear is opposite to the direction of rotation of driving gear only if______

a. even number of idler gears are present
b. odd number of idler gears are present

 Answer  Explanation ANSWER: even number of idler gears are present Explanation: No explanation is available for this question!

8)   Which of the following statements is/are true for gear drives?

a. They can be used for long centre distances
b. They are used to transmit power between non-intersecting and parallel shafts
c. They cannot be used for high reduction ratios
d. All of the above
 Answer  Explanation ANSWER: They are used to transmit power between non-intersecting and parallel shafts Explanation: No explanation is available for this question!

9)   In which power transmitting drive polygon effect is observed?

a. Belt drive
b. Chain drive
c. Both a. and b.
d. None of the above
 Answer  Explanation ANSWER: Chain drive Explanation: No explanation is available for this question!

10)   What is meant by gear ratio?

a. The ratio of pinion speed and gear speed
b. The ratio of number of teeth on pinion and number of teeth on gear
c. Both a. and b.
d. None of the above
 Answer  Explanation ANSWER: The ratio of pinion speed and gear speed Explanation: No explanation is available for this question!