Electrical Drive Systems MCQ [Free PDF] – Objective Question Answer for Electrical Drive Systems Quiz

11. Full form of MCC is ____________

A. Motor control center
B. Motor counter center
C. Machine control center
D. Motor coil counter

Answer: A

The full form of MCC is the Motor control center. It controls the power of system drives. There can many MCCs exist in an area.

 

12. Full form of PCC is ____________

A. Producer control center
B. Poor counter center
C. Power control center
D. Power coil counter

Answer: C

The full form of PCC is the Power control center. They receive power from the main power distribution center.

 

13. Current Chopping is most severe in which one of the following?

A. Air Blast Circuit Breaker
B. Oil Circuit Breaker
C. Air Break Circuit Breaker
D. Vacuum Circuit Breaker

Answer: A

Current chopping is most severe in the case of an air blast circuit breaker. Resistance switching is used to avoid the problem of current chopping.

 

14. Oil circuit breaker is mainly used in _____________

A. Synchronous machine
B. Induction machine
C. DC machine
D. Transformer

Answer: D

An oil circuit breaker is mainly used in transformers. The oil acts as a coolant for the transformer. When a fault occurs in the transformer oil decomposes in the gases.

 

15. Full form of PLC is ____________

A. Programmable Logic Controller
B. Programmable Language Controller
C. Peterson Language Counter
D. Programmable Logic Counter

Answer: A

The full form of PLC is a Programmable logic controller. It is a computer control system that monitors input states and makes decisions based upon a program to control output states.

 

16. Relay is an electromechanical switch.

A. True
B. False

Answer: A

Relay is an electromechanical switch. It uses electrical signals as input and mechanical operation as output.

 

17. Mho relay is used in the medium transmission line.

A. True
B. False

Answer: B

Mho relay is an inherent directional relay. It is used in the long transmission line. It is less affected by power surges.

 

18. Full form of LED is _____________

A. Light Emitting Diode
B. Light Emission Digital
C. Light Energy Diode
D. Light Energy Digital

Answer: A

The full form of LED is a light-emitting diode. It converts light energy into electrical energy. It works in the reverse bias region.

 

19. Inter turn fault can be detected by using __________

A. Oil circuit breaker
B. Split phase relay
C. SF6 circuit breaker
D. Vertical breaker

Answer: B

Inter-turn fault mainly occurs in the winding of the rotor side of the alternator. They can be detected by using the split-phase relaying technique.

 

20. Calculate the value of the fault impedance if the fault voltage is 2 V and the fault current is 4 A.

A. .5 ohm
B. .2 ohm
C. .4 ohm
D. .6 ohm

Answer: A

The value of the fault impedance is the ratio of fault voltage and fault current. It is expressed in ohms.

Z=V/I=2/4=.5 ohm.

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21. Reactance relay is used in _______

A. Medium line
B. Short transmission line
C. Lossless line
D. Long transmission line

Answer: B

Reactance relay is used in a short transmission line. The reactance relay is independent of the resistance value. It protects the short transmission line from any fault.

 

22. Load interrupter operated at ________

A. No-load
B. Full load
C. Half of the full load
D. One-fourth of the full load

Answer: B

A load interrupter is used to avoid overloading conditions. It separates the under-stressed area from the line. It operates at full load.

 

23. Calculate the maximum frequency for ASCI using the data: R=1 kΩ, C=1 μF.

A. 250 Hz
B. 280 Hz
C. 300 Hz
D. 320 Hz

Answer: A

The minimum time period for ASCI is a

4×R×C=4×1×1×.001=4 msec.

The total time is the sum of charging and discharging time. The maximum frequency is 1÷f=250 Hz.

 

24. Calculate the PIV for the Full-wave bridge rectifier if the peak value of the supply voltage is 50.

A. 72.5 V
B. 72.8 V
C. 70.7 V
D. 76.1 V

Answer: C

The peak inverse voltage for the Full-wave bridge rectifier is

Vm = √2×230=70.7 V.

The peak inverse is the maximum negative voltage across the thyristor.

 

25. In single-phase, RLE load, calculate the Peak inverse voltage using the data: (Vs)r.m.s = 9 V, f = 50 Hz, E = 40 V.

A. 52.2 V
B. 52.7 V
C. 59.7 V
D. 52.9 V

Answer: B

In a single-phase, RLE loads the peak inverse voltage across the thyristor

VT = Vm+E = 52.7 V.

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