MCQ on Switchgear Protection for Electrical Engineering

Multiple Choice Questions (MCQ) on Switchgear Protection for Electrical Engineering


MCQ on Switchgear Protection for Electrical Engineering
1. The main function of a fuse is to 
(a) protect the line 
(b) open the circuit 
(c) protect the appliance 
(d) prevent excessive currents 
(e) none of the above 

Ans: d

2. With which of the following, a circuit breaker must be equipped for remote operation? 
(a) Inverse time trip 
(b) Time-delay trip 
(c) Shunt trip 
(d) None of the above 
(e) All of the above 



Ans: c

3. Fault diverters are basically 
(a) fuses 
(b) relays 
(c) fast switches 
(d) circuit breakers 

Ans: c

4. Arc in a circuit behaves as 
(a) a capacitive reactance 
(b) an inductive reactance 
(c) a resistance increasing with voltage rise across the arc 
(d) a resistance decreasing with voltage rise across the arc 

Ans: d

5. Overload relays are of…… type. 
(a) induction 
(b) solid state 
(c) thermal 
(d) electromagnetic 
(e) all above 

Ans: e

6. Circuit breakers usually operate under 
(a) transient state of short-circuit current 
(b) sub-transient state of short-circuit current 
(c) steady state of short-circuit current 
(d) after D.C. component has ceased 

Ans: a

7. Air blast circuit breaker is used for 
(a) over currents 
(b) short duty 
(c) intermittent duty 
(d) repeated duty 

Ans: d

8. The voltage appearing across the contacts after opening of the circuit breaker is called______voltage. 
(a) recovery 
(b) surge 
(c) operating 
(d) arc 
(e) none of the above 

Ans: a

9. Ionization in circuit breaker is facilitated by 
(a) high temperature 
(b) increase of mean free path 
(c) increasing field strength 
(d) all of the above 

Ans: d

10. The time of closing the cycle, in modern circuit breakers is 
(a) 0.003 sec 
(b) 0.001 sec 
(c) 0.01 sec 
(d) 0.10 sec 
(e) none of the above 

Ans: a

11. Insulation resistance of high voltage circuit breakers is more than 
(a) 1 mega ohms 
(b) 10 mega ohms 
(c) 100 mega ohms 
(d) 500 mega ohms 

Ans: c

12. The ground wire should not be smaller than No ______ copper. 
(a) 2 
(b) 4 
(c) 6 
(d) 10 

Ans: d

13. In Railway applications ______ circuit breaker is used. 
(a) SFe 
(b) bulk oil 
(c) minimum oil 
(d) air break 

Ans: d



14. Wave trap is used to trap waves of
(a) power frequencies
(b) higher frequencies entering generator or transformer units
(c) either of the above
(d) none of the above

Ans: b

15. For the protection of power station buildings against direct strokes, the requirements are
(a) interception
(b) interception and conduction
(c) interception, conduction and dissipation
(d) interception, conduction, dissipation and reflection
(e) none of the above

Ans: c

16. The line insulation is the insulation level of the station equipment.
(a) less than
(b) same as
(c) more than
(d) proportional to
(e) not directly related with

Ans: e

17. Bus coupler is very essential in arrangement
(a) single bus
(b) double bus, double breaker
(c) main and transfer bus
(d) all of the above

Ans: c

18. For cost and safety, the outdoor substations are installed for voltages above
(a) 11 kV
(b) 33 kV
(c) 60kV
(d) 110kV

Ans: b

19. The short circuit in any winding of the transformer is the result of
(a) mechanical vibration
(b) insulation failure
(c) loose connection
(d) impulse voltage

Ans: d

20. A _______ is used to measure the stator winding temperature of the generator.
(a) thermocouple
(b) pyrometer
(c) resistance thermometer
(d) thermometer

Ans: c

21. The relay with inverse time characteristic will operate within
(a) 1.5 sec
(b) 5 to 10 sec
(c) 5 to 20 sec
(d) 20 to 30 sec
(e) none of the above

Ans: b

22. Which of the following circuit breakers has high reliability and minimum maintenance?
(a) Air blast circuit breakers
(b) Circuit breaker with SF6 gas
(c) Vacuum circuit breakers
(d) Oil circuit breakers

Ans: b

23. Over voltage, protection is recommended for
(a) hydro-electric generators
(b) steam turbine generators
(c) gas turbine generators
(d) all of the above
(e) none of the above

Ans: d

24. Air blast circuit breakers for 400 kV power system are designed to operate in
(a) 100 microsecond
(b) 50 millisecond
(c) 0.5 sec
(d) 0.1 sec

Ans: b

25. The torque produced in induction type relay (shaded pole structure) is
(a) inversely proportional to the current
(b) inversely proportional to the square of the current
(c) proportional to the current
(d) proportional to the square of the current

Ans: b

26. A fuse is never inserted in
(a) neutral wire
(b) negative of D.C. circuit
(c) positive of D.C. circuit
(d) phase dine

Ans: a

27. By which of the following methods major portion of the heat generated in a H.R.C. fuse is dissipated?
(a) Radiation
(b) Convection
(c) Conduction
(d) All of the above

Ans: c


Tags -
#mcq on switchgear and protection
#power system protection and switchgear question bank
#protection and switchgear question bank with answers
#circuit breaker objective questions
#electrical engineering mcq

Share:

0 comments:

Post a Comment

Popular Posts

About

ElectricalNotes4u is a Blog for Electrical Engineering Students who want to learn Electrical Engineering online. We will Provide You Notes on all Major subject of electrical engineering. We also Provide Important MCQ that will help you to Prepare for Competitive Exam.