Question 1

Protection by fuses is generally not used beyond

Accepted Answer

A) 20 A 
B) 50 A 
C) 100 A 
D) 200 A 
A) 20 A 
B) 50 A 
C) 100 A 
D) 200 A C

Question 2

If the fault occurs near the impedance relay, the VII ratio will be

Accepted Answer

A) constant for all distances 
B) lower than that of if fault occurs away from the relay 
C) higher than that of if fault occurs away from the relay 
D) none of the above 
A) constant for all distances 
B) lower than that of if fault occurs away from the relay 
C) higher than that of if fault occurs away from the relay 
D) none of the above B

Question 3

The inverse definite mean time relays are used for over current and earth fault protection of transformer against

Accepted Answer

A) heavy loads 
B) internal short-circuits 
C) external short-circuits 
D) all of the above 
A) heavy loads 
B) internal short-circuits 
C) external short-circuits 
D) all of the above B

Question 4

The power loss is an important factor for the design of

Accepted Answer

A) transmission line 
B) motor 
C) generator 
D) feeder 
A) transmission line 
B) motor 
C) generator 
D) feeder

Question 5

Air blast circuit breakers for 400 kV power system are designed to operate in

Accepted Answer

A) 100 microsecond 
B) 50 millisecond 
C) 0.5 sec 
D) 0.1 sec 
A) 100 microsecond 
B) 50 millisecond 
C) 0.5 sec 
D) 0.1 sec

Question 6

Admittance relay is _______ relay.

Accepted Answer

A) impedance 
B) directional 
C) non-directional 
D) none of the above 
A) impedance 
B) directional 
C) non-directional 
D) none of the above

Question 7

The fuse rating is expressed in terms of

Accepted Answer

A) current 
B) voltage 
C) VAR 
D) kVA 
A) current 
B) voltage 
C) VAR 
D) kVA

Question 8

On which of the following effects of electric current a fuse operates ?

Accepted Answer

A) Photoelectric effect 
B) Electrostatic effect 
C) Heating effect 
D) Magnetic effect 
A) Photoelectric effect 
B) Electrostatic effect 
C) Heating effect 
D) Magnetic effect

Question 9

A fuse is never inserted in

Accepted Answer

A) neutral wire 
B) negative of D.C. circuit 
C) positive of D.C. circuit 
D) phase dine 
A) neutral wire 
B) negative of D.C. circuit 
C) positive of D.C. circuit 
D) phase dine

Question 10

The torque produced in induction type relay (shaded pole structure) is

Accepted Answer

A) inversely proportional to the current 
B) inversely proportional to the square of the current 
C) proportional to the current 
D) proportional to square of the current 
A) inversely proportional to the current 
B) inversely proportional to the square of the current 
C) proportional to the current 
D) proportional to square of the current

Question 11

A fuse in a motor circuit provides protection against

Accepted Answer

A) overload 
B) short-circuit and overload 
C) open circuit, short-circuit and overload 
D) none of the above 
A) overload 
B) short-circuit and overload 
C) open circuit, short-circuit and overload 
D) none of the above

Question 12

Arc in a circuit breaker is interrupted at

Accepted Answer

A) zero current 
B) maximum current 
C) minimum voltage 
D) maximum voltage 
A) zero current 
B) maximum current 
C) minimum voltage 
D) maximum voltage

Question 13

The material used for fuse must have

Accepted Answer

A) low melting point and high specific resistance 
B) low melting point and -low specific resistance 
C) high melting point and low specific resistance 
D) low melting point and any specific resistance 
A) low melting point and high specific resistance 
B) low melting point and -low specific resistance 
C) high melting point and low specific resistance 
D) low melting point and any specific resistance

Question 14

Over voltage protection is recommended for

Accepted Answer

A) hydro-electric generators 
B) steam turbine generators 
C) gas turbine generators 
D) all of the above 
A) hydro-electric generators 
B) steam turbine generators 
C) gas turbine generators 
D) all of the above

Question 15

The inductive interference between power and communication line can be minimized by

Accepted Answer

A) transposition of the power line 
B) transposition of the communication line 
C) both (a) and (b) 
D) increasing the distance between the conductors 
A) transposition of the power line 
B) transposition of the communication line 
C) both (a) and (b) 
D) increasing the distance between the conductors

Question 16

Series capacitors are used to

Accepted Answer

A) compensate for line inductive reactance 
B) compensate for line capacitive reactance 
C) improve line voltage 
D) none of the above 
A) compensate for line inductive reactance 
B) compensate for line capacitive reactance 
C) improve line voltage 
D) none of the above

Question 17

The fuse blows off by

Accepted Answer

A) burning 
B) arcing 
C) melting 
D) none of the above 
A) burning 
B) arcing 
C) melting 
D) none of the above

Question 18

Which of the following circuit breakers has high reliability and minimum maintenance ?

Accepted Answer

A) Air blast circuit breakers 
B) Circuit breaker with SF6 gas 
C) Vacuum circuit breakers 
D) Oil circuit breakers 
A) Air blast circuit breakers 
B) Circuit breaker with SF6 gas 
C) Vacuum circuit breakers 
D) Oil circuit breakers

Question 19

An isolator is installed

Accepted Answer

A) to operate the relay of circuit breaker 
B) as a substitute for circuit breaker 
C) always independent of the position of circuit breaker 
D) generally on both sides of a circuit breaker 
A) to operate the relay of circuit breaker 
B) as a substitute for circuit breaker 
C) always independent of the position of circuit breaker 
D) generally on both sides of a circuit breaker

Question 20

What will be the reflection co-efficient of the wave of load connected to transmission line if surge impedance of the line is equal to load ?

Accepted Answer

A) Zero 
B) Unity 
C) Infinity 
D) None of the above 
A) Zero 
B) Unity 
C) Infinity 
D) None of the above

Protection by fuses is generally not used beyond

If the fault occurs near the impedance relay, the VII ratio will be

The inverse definite mean time relays are used for over current and earth fault protection of transformer against

The power loss is an important factor for the design of

Air blast circuit breakers for 400 kV power system are designed to operate in

Admittance relay is _______ relay.

The fuse rating is expressed in terms of

On which of the following effects of electric current a fuse operates ?

A fuse is never inserted in

The torque produced in induction type relay (shaded pole structure) is

A fuse in a motor circuit provides protection against

Arc in a circuit breaker is interrupted at

The material used for fuse must have

Over voltage protection is recommended for

The inductive interference between power and communication line can be minimized by

Series capacitors are used to

The fuse blows off by

Which of the following circuit breakers has high reliability and minimum maintenance ?

An isolator is installed

What will be the reflection co-efficient of the wave of load connected to transmission line if surge impedance of the line is equal to load ?

Electrical Components and Protective Relays

Electrical Protection and Transmission Systems

Electrical Substation Equipment and Protection Systems

Electrical Protection and Switchgear Systems

Electrical Protection and Circuit Breakers

Filters

Exam 4: Electrical Protection and Circuit Breakers

Protection by fuses is generally not used beyond

If the fault occurs near the impedance relay, the VII ratio will be

The inverse definite mean time relays are used for over current and earth fault protection of transformer against

The power loss is an important factor for the design of

Air blast circuit breakers for 400 kV power system are designed to operate in

Admittance relay is _______ relay.

The fuse rating is expressed in terms of

On which of the following effects of electric current a fuse operates ?

A fuse is never inserted in

The torque produced in induction type relay (shaded pole structure) is

A fuse in a motor circuit provides protection against

Arc in a circuit breaker is interrupted at

The material used for fuse must have

Over voltage protection is recommended for

The inductive interference between power and communication line can be minimized by

Series capacitors are used to

The fuse blows off by

Which of the following circuit breakers has high reliability and minimum maintenance ?

An isolator is installed

What will be the reflection co-efficient of the wave of load connected to transmission line if surge impedance of the line is equal to load ?

Electrical Components and Protective Relays

Electrical Protection and Transmission Systems

Electrical Substation Equipment and Protection Systems

Electrical Protection and Switchgear Systems

Electrical Protection and Circuit Breakers

Filters