Question 1

What is the actuating quantity for the relays?

Accepted Answer

A) Magnitude 
B) Frequency 
C) Phase angle 
D) All of these 
A) Magnitude 
B) Frequency 
C) Phase angle 
D) All of these D

Question 2

What is the purpose of back up protection?

Accepted Answer

A) To increase the speed 
B) To increase the reach 
C) To leave no blind spot 
D) To guard against failure of primary 
A) To increase the speed 
B) To increase the reach 
C) To leave no blind spot 
D) To guard against failure of primary D

Question 3

Rate of rise of restriking voltage depends

Accepted Answer

A) Type of circuit breaker. 
B) Inductance of the system only. 
C) Capacitance of the system only. 
D) Inductance and capacitance of the system 
A) Type of circuit breaker. 
B) Inductance of the system only. 
C) Capacitance of the system only. 
D) Inductance and capacitance of the system D

Question 4

What does the third part consist of?

Accepted Answer

A) Primary winding of a current CT which is connected in series with the line to be protected. 
B) Secondary of the CT and the operating coil. 
C) Tripping circuit. 
D) All of these. 
A) Primary winding of a current CT which is connected in series with the line to be protected. 
B) Secondary of the CT and the operating coil. 
C) Tripping circuit. 
D) All of these.

Question 5

Isolator in substation is open under ------------- condition?

Accepted Answer

A) No load 
B) Short Circuit 
C) Full Load 
D) Any of the above 
A) No load 
B) Short Circuit 
C) Full Load 
D) Any of the above

Question 6

For measuring positive, negative and zero sequence voltages in a system, the reference is taken as

Accepted Answer

A) Neutral of the system only. 
B) Ground only. 
C) For zero sequence neutral and for positive and negative the ground. 
D) None of the above. 
A) Neutral of the system only. 
B) Ground only. 
C) For zero sequence neutral and for positive and negative the ground. 
D) None of the above.

Question 7

For reducing tower footing resistance it is better to use

Accepted Answer

A) Chemical and ground rods only. 
B) Chemical and counterpoise only. 
C) Ground rod and counterpoise only. 
D) Chemical, ground rods and counterpoise. 
A) Chemical and ground rods only. 
B) Chemical and counterpoise only. 
C) Ground rod and counterpoise only. 
D) Chemical, ground rods and counterpoise.

Question 8

The fuse wire, in D.C. circuits, is inserted in

Accepted Answer

A) negative circuit only 
B) positive circuit only 
C) both (a) and (b) 
D) either (a) or (b) 
A) negative circuit only 
B) positive circuit only 
C) both (a) and (b) 
D) either (a) or (b)

Question 9

A reactance relay is

Accepted Answer

A) Voltage restrained directional relay. 
B) Directional restrained over-current relay. 
C) Voltage restrained over-current relay. 
D) None of the above. 
A) Voltage restrained directional relay. 
B) Directional restrained over-current relay. 
C) Voltage restrained over-current relay. 
D) None of the above.

Question 10

A fault is more severe from the view point of RRRV if is a

Accepted Answer

A) Short line fault. 
B) Medium length line fault. 
C) Long line fault. 
D) None of these. 
A) Short line fault. 
B) Medium length line fault. 
C) Long line fault. 
D) None of these.

Question 11

On what factor does the operating speed of the relay depend upon?

Accepted Answer

A) Rate of flux built up 
B) Armature core air gap 
C) spring tension 
D) All of these 
A) Rate of flux built up 
B) Armature core air gap 
C) spring tension 
D) All of these

Question 12

Oil switches are employed for

Accepted Answer

A) low currents circuits 
B) low voltages circuits 
C) high voltages and large currents circuits 
D) all circuits 
A) low currents circuits 
B) low voltages circuits 
C) high voltages and large currents circuits 
D) all circuits

Question 13

A balanced 3-phase system consists of

Accepted Answer

A) zero sequence currents only 
B) positive sequence currents only 
C) negative and zero sequence currents 
D) zero, negative and positive sequence currents 
A) zero sequence currents only 
B) positive sequence currents only 
C) negative and zero sequence currents 
D) zero, negative and positive sequence currents

Question 14

By which of the following methods major portion of the heat generated in a H.R.C. fuse is dissipated ?

Accepted Answer

A) Radiation 
B) Convection 
C) Conduction 
D) All of the above 
A) Radiation 
B) Convection 
C) Conduction 
D) All of the above

Question 15

Which device is used for protection of equipment from from damage caused by overload or short circuit?

Accepted Answer

A) CVT 
B) Circuit Breaker 
C) Current Transformer 
D) Lighting Arrester 
A) CVT 
B) Circuit Breaker 
C) Current Transformer 
D) Lighting Arrester

Question 16

In a single bus-bar system there will be complete shut down when

Accepted Answer

A) fault occurs on the bus itself 
B) fault occurs on neutral line 
C) two or more faults occur simultaneously 
D) fault occurs with respect to earthing 
A) fault occurs on the bus itself 
B) fault occurs on neutral line 
C) two or more faults occur simultaneously 
D) fault occurs with respect to earthing

Question 17

Earthling switch is used for

Accepted Answer

A) measuring of safety voltage 
B) protection of equipment from ground faults 
C) discharging residual energies 
D) all of the above 
A) measuring of safety voltage 
B) protection of equipment from ground faults 
C) discharging residual energies 
D) all of the above

Question 18

Positive, negative and zero sequence impedances of a solidly grounded system under steady state condition always follow the relations

Accepted Answer

A) Z4>Z2>Z0 
B) Z2>Z4>Z0 
C) Z0>Z4>Z2 
D) None of the above 
A) Z4>Z2>Z0 
B) Z2>Z4>Z0 
C) Z0>Z4>Z2 
D) None of the above

Question 19

The information to the circuit breaker under fault conditions is provided by

Accepted Answer

A) relay 
B) rewirable fuse 
C) H.R.C. only 
D) all of the above 
A) relay 
B) rewirable fuse 
C) H.R.C. only 
D) all of the above

Question 20

Phase comparators in case of static relays and electro-mechanical relays normally are

Accepted Answer

A) Sine and cosine comparators respectively 
B) Cosine and sine comparators respectively. 
C) Both are cosine comparators. 
D) Both are sing comparators. 
A) Sine and cosine comparators respectively 
B) Cosine and sine comparators respectively. 
C) Both are cosine comparators. 
D) Both are sing comparators.

What is the actuating quantity for the relays?

What is the purpose of back up protection?

Rate of rise of restriking voltage depends

What does the third part consist of?

Isolator in substation is open under ------------- condition?

For measuring positive, negative and zero sequence voltages in a system, the reference is taken as

For reducing tower footing resistance it is better to use

The fuse wire, in D.C. circuits, is inserted in

A reactance relay is

A fault is more severe from the view point of RRRV if is a

On what factor does the operating speed of the relay depend upon?

Oil switches are employed for

A balanced 3-phase system consists of

By which of the following methods major portion of the heat generated in a H.R.C. fuse is dissipated ?

Which device is used for protection of equipment from from damage caused by overload or short circuit?

In a single bus-bar system there will be complete shut down when

Earthling switch is used for

Positive, negative and zero sequence impedances of a solidly grounded system under steady state condition always follow the relations

The information to the circuit breaker under fault conditions is provided by

Phase comparators in case of static relays and electro-mechanical relays normally are

Electrical Components and Protective Relays

Electrical Protection and Transmission Systems

Electrical Substation Equipment and Protection Systems

Electrical Protection and Circuit Breakers

Electrical Protection and Circuit Breakers

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Exam 5: Electrical Protection and Switchgear Systems

What is the actuating quantity for the relays?

What is the purpose of back up protection?

Rate of rise of restriking voltage depends

What does the third part consist of?

Isolator in substation is open under ------------- condition?

For measuring positive, negative and zero sequence voltages in a system, the reference is taken as

For reducing tower footing resistance it is better to use

The fuse wire, in D.C. circuits, is inserted in

A reactance relay is

A fault is more severe from the view point of RRRV if is a

On what factor does the operating speed of the relay depend upon?

Oil switches are employed for

A balanced 3-phase system consists of

By which of the following methods major portion of the heat generated in a H.R.C. fuse is dissipated ?

Which device is used for protection of equipment from from damage caused by overload or short circuit?

In a single bus-bar system there will be complete shut down when

Earthling switch is used for

Positive, negative and zero sequence impedances of a solidly grounded system under steady state condition always follow the relations

The information to the circuit breaker under fault conditions is provided by

Phase comparators in case of static relays and electro-mechanical relays normally are

Electrical Components and Protective Relays

Electrical Protection and Transmission Systems

Electrical Substation Equipment and Protection Systems

Electrical Protection and Circuit Breakers

Electrical Protection and Circuit Breakers

Filters