Question 1 of 33

1. What is the purpose of LCD on basic operator panel in D.C drive?

Indicate the fault

Display the speed

Display availability of supply

Monitor the parameter

Question 1 of 33

Question 2 of 33

2. What is the full form of B.O.P in D.C drive?

Bridge Operator Programme

Bridge Operation Panel

Basic Operational Panel

Basic Operation Programme

Question 2 of 33

Question 3 of 33

3. What is the reason for using shielded cable for connecting low level signal circuits in DC drives?

Easy for connection

Protects from mechanical injuries

Eliminates the electrical interference

Good appearance

Question 3 of 33

Question 4 of 33

4. Which type of machine in industries is provided with multi-motor electric drive?

Rolling machine

Shearing machine

Air Compressor

Heavy duty electric drilling machine

Question 4 of 33

Question 5 of 33

5. What is the function of IGBT in AC drive?

Stabilize the output voltage from the rectifier

Converts incoming A.C power into D.C power output

Smoothening incoming A.C supply

Controls the power delivered to the motor

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Question 6 of 33

6. Why are A.C drives better suited for high speed operation?

High starting torque

Robust in construction

Having lighter gauge winding

No brushes and commutation

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Question 7 of 33

7. What is IGBT in VF drive?

Inverter switching device

D.C bus switching device

Field supply switching device

Rectifier switching device

Question 7 of 33

Question 8 of 33

8. What is the main use of A.C drive?

Group drive motors

Interlocking system in industries

Control stepless speed in motors

High starting torque

Question 8 of 33

Question 9 of 33

9. What is the purpose of PROG/DATA button in BOP of AC drive?

To change the parameter setting

To display the data status of frequency and current

To store the entered data and factory stored data

To display the data direction of rotation forward/REV

Question 9 of 33

Question 10 of 33

10. Which drive is classified according to mode of operation?

Group drive

Continuous duty drive

Individual drive

Manual drive

Question 10 of 33

Question 11 of 33

11. Which device controls the speed of A.C motor in A.C drive?

Speed feedback technology box

Field supply unit (FSU)

COMMS technology box

Microprocessor based electronic device

Question 11 of 33

Question 12 of 33

12. What is the function of Field Supply Unit (FSU) in DC drive?

Provides a constant voltage to the armature of the motor

Provides variable voltage to the field winding of motor

Provides a constant voltage to the field winding of motor

Produces required firing current to the firing circuit

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Question 13 of 33

13. How can the base speed of D.C shunt motor be increased by using D.C drive?

By increasing the supply voltage

By reducing the armature voltage

By increasing the field current

By reducing the field current

Question 13 of 33

Question 14 of 33

14. What is the purpose of JOG key in control panel of D.C drive?

Restart the motor

Reverse the direction of motor

Stop the motor

Inching operation

Question 14 of 33

Question 15 of 33

15. Which is proportional to the torque in D.C motor?

Field current

Armature current

Terminal voltage

Back e.m.f

Question 15 of 33

Question 16 of 33

16. What is the advantage of AC drive compared to DC drive?

Fast response and wide speed range of control

Power circuit and control circuits are simple

Requires less space

Installation and running cost is less

Question 16 of 33

Question 17 of 33

17. Which is the application of single quadrant loads operating in first quadrant in drives?

Centrifugal pumps

Conveyors

Hoists

Elevators

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Question 18 of 33

18. Why are A.C drives mostly used in process plants?

Robust in construction

Very high starting torque

Maintenance free long life

Easy to operate

Question 18 of 33

Question 19 of 33

19. Which is the correct sequence operation of key button in BOP of AC drive to change the direction of rotation?

Press ON → OFF → REV → ON

Press OFF → REV → ON

Press ON → REV → ON

Press ON → REV → OFF → ON

Question 19 of 33

Question 20 of 33

20. Which is the classification of drive according to dynamics and transients?

Short time duty drive

Variable position control drive

Intermittent duty drive

Automatic control drive

Question 20 of 33

Question 21 of 33

21. What is the name of the characteristic curve in D.C drive?

Torque Vs field current characteristic

Field current Vs armature current characteristic

Speed Vs armature current characteristic

Speed Vs torque characteristic

Question 21 of 33

Question 22 of 33

22. Which power modulator is used in the electric drive system?

Servo controlled voltage stabilizer

Phase sequence indicator

Cyclo converters

Frequency multiplier

Question 22 of 33

Question 23 of 33

23. What is the name of the component marked as 'X' in the block diagram of AC drive?

A.C motor

Rectifier

D.C bus

Inverter

Question 23 of 33

Question 24 of 33

24. Which control system consumes very low power for motion control in AC and DC motors?

Voltage control

Field control

Armature control

Drives control

Question 24 of 33

Question 25 of 33

25. What is the function of VSI drives?

Converts A.C to A.C

Converts A.C to D.C

Converts D.C to D.C

Converts D.C to A.C

Question 25 of 33

Question 26 of 33

26. How can constant torque be obtained from armature and field controlled drives?

By reducing the field current

By controlling the armature voltage

By reducing the armature current

By increasing the field current

Question 26 of 33

Question 27 of 33

27. Which type of sensing unit is employed in drive systems?

Resistance temperature detector

Speed sensing

Photo voltaic cell

Opto coupler

Question 27 of 33

Question 28 of 33

28. What is the purpose of LCD in Basic Operator Panel (BOP) in AC drive?

Indicate the status of drive

Indicate the display error in reading

Monitor the parameter of AC drive

Indicate the incorrect operation of BOP

Question 28 of 33

Question 29 of 33

29. What is electric drive?

A device used as prime mover for generator

A machine converts mechanical energy into electrical

An electro mechanical device for controlling motor

A device converts A.C to D.C supply

Question 29 of 33

Question 30 of 33

30. Why is it necessary to keep V/F ratio constant in a drive?

Maintain the speed of motor constant

Keep the stator flux maximum

Maintain the rated torque at all speeds

Maintain the rotor current minimum

Question 30 of 33

Question 31 of 33

31. Which control system is used for Eddy current drives?

Rectifier controller

Slip controller

DC chopper controller

AC voltage controller

Question 31 of 33

Question 32 of 33

32. What is the disadvantage of DC drive?

More expensive than AC drive for high capacity motor

Installation of DC drives is more complicated

Not suitable for high speed operation

More complex with a single power conversion

Question 32 of 33

Question 33 of 33

33. What is the function of power controller in drive circuits?

It maintain the torque at low voltage conditions

It reduce motor current during transient operation

It sounds an alarm in no load conditions

It detects the overloading condition of motor

Question 33 of 33