Electrical Drive MCQ

1. The basic elements of an electric drive are :

(a) electric motor and the transmission system.
(b) electric motor, the transmission and control system.
(c) the transmission and control system.
(d) electric motor and conversion equipment.

2. Electric drive is becoming more and more popular because

(a) it is simple, clean, compact and reliable.
(b) it provides easy and smooth control, flexibility in layout easy starting and facility for remote control.
(c) it is cheaper in initial as well as in maintenance cost.
(d) all of the above.

3. The main drawback of electric drive is that

(a) it is cumbersome drive.
(b) it is costlier in initial as well as in maintenance cost.
(c) electrical power supply failure makes the drive standstill.
(d) all of the above.

4. An existing workshop is to be changed over from an engine drive to an electric drive. The type of drive likely to be adopted is

(a) individual drive.
(b) group drive.
(c) multimotor drive.
(d) any of the above.

5. The type of drive used for a paper mill requiring constant speed operation and flexibility of control is

(a) group drive.
(b) multimotor drive.
(c) individual or multimotor drive.
(d) individual drive.

6. Introduction of automation in production processes has become possible only because of use of

(a) an electric drive.
(b) group drives.
(c) individual and multimotor drives.
(d) individual drive.

7. The selection of an electric motor is governed by

(a) nature of load to be handled.
(b) environmental conditions.
(c) nature of electric supply available.
(d) all of the above.

8. DC motors are still preferred for use in

(a) electric excavators, steel mills and cranes.
(b) lathes and machine tools.
(c) flour mills and jaw crushers.
(d) paper industry.

9. The least significant electrical characteristic in selection of electric motor for a flour mill is

(a) starting characteristics.
(b) braking.
(c) running characteristics.
(d) efficiency.

10. The least significant feature while selecting a motor for centrifugal pump is

(a) speed control.
(b) power rating of motor.
(c) operating speed.
(d) starting characteristics.

11. A typical active load is

(a) hoist.
(b) blower.
(c) pump.
(d) lathe.

12. An elevator drive is required to operate in

(a) one quadrant only.
(b) two quadrants.
(c) three quadrants.
(d) four quadrants.

13. Load torque constant at all speeds is represented by a

(a) fan.
(b) compressor.
(c) centrifugal pump load.

14. An example of a motor having short-time duty is found in

(a) centrifugal pumps.
(b) crane drives.
(c) drilling machines.
(d) all of the above.

15. The load, for which the motor always starts on load is

(a) fan motor.
(b) conveyor motor.
(c) flour mill motor.
(d) all of the above.

16. The load cycle for a motor driving a power press will be

(a) continuous.
(b) variable.
(c) intermittent and variable.
(d) continuous but periodical.

17. The application(s) that need(s) frequent starting and stopping is/ are

(a) paper mills.
(b) lifts and hoists.
(c) blowers and fans.
(d) grinding mills.

18. An electric motor, in jaw crushers, has to often start against

(a) heavy load.
(b) normal load.
(c) medium load.
(d) low load.

19. The application(s) in which the load on the motor changes in cyclic order is/are

(a) rolling mills.
(b) cranes.
(c) electric shovels.
(d) all of the above.

20. The machine having heavy fluctuation of load is

(a) lathe.
(b) planer.
(c) punching machine.
(d) printing machine.