Switchgear and Protection Quiz | Switchgear and Protection Objective Type Questions and Answers

Questions
21 Induction cup relay is operated due to changes in
A Current
B Voltage
C Impedance
D All Of The Above

Answer: All Of The Above
22 Which of the following statements is incorrect ?
A Lightning arrestors are used before the switchgear
B Shunt reactors are used as compensation reactors
C The peak short current is (1.8 xV2) times the A.C. component
D The MVA at fault is equal to base MVA divided by per unit equivalent fault reactance

Answer: Lightning arrestors are used before the switchgear
23 Bus coupler is very essential in arrangement
A Single Bus
B Double Bus, Double Breaker
C Main And Transfer Bus
D None of the above

Answer: Main And Transfer Bus
24 For cost and safety, the outdoor substations are installed for voltages above
A 11 kV
B 33 kV
C 60kV
D 110kV

Answer: 33 kV
25 Distance relays are generally
A Split-Phase Relays
B Reactance Relays
C Impedance Relays
D None Of The Above

Answer: None Of The Above
26 A _______ is used to measure the stator % winding temperature of the generator.
A Thermocouple
B Pyrometer
C Resistance Thermometer
D Thermometer

Answer: Resistance Thermometer
27 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

Answer: 5 to 10 sec
28 Which of the following devices will receive voltage surge first travelling on the transmission line ?
A Lightning arresters
B Relays
C Step-down transformer
D Switchgear

Answer: Lightning arresters
29 Series reactors should have
A low resistance
B high resistance
C low impedance
D All Of The Above

Answer: low resistance
30 Arc in a circuit breaker is interrupted at
A zero current
B maximum current
C minimum voltage
D maximum voltage

Answer: zero current
31 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 ?
A Zero
B Unity
C Infinity
D None of the above

Answer: Zero
32 Over voltage protection is recommended for
A hydro-electric generators
B steam turbine generators
C gas turbine generators
D all of the above

Answer: all of the above
33 Overfluxing protection is recommended for
A distribution transformer
B generator transformer of the power plant
C auto-transformer of the power plant
D station transformer of the power plant

Answer: generator transformer of the power plant
34 Admittance relay is _______ relay.
A Impedance
B Directional
C Non-Directional
D None Of The Above

Answer: Directional
35 The material used for fuse must have
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

Answer: low melting point and high specific resistance
36 The steady state stability of the power system can be increased by
A connecting lines in parallel
B connecting lines in series
C using machines of high impedance
D all of the above

Answer: connecting lines in parallel
37 A fuse is connected
A either in series or in parallel with circuit
B in parallel with circuit
C in series with circuit
D None Of The Above

Answer: in series with circuit
38 A fuse is never inserted in
A neutral wire
B negative of D.C. circuit
C positive of D.C. circuit
D None Of The Above

Answer: neutral wire
39 A switchgear is device used for
A interrupting an electrical circuit
B switching an electrical circuit 111
C switching and controlling an electrical circuit
D switching, controlling and protecting the electrical circuit and equipment

Answer: interrupting an electrical circuit
40 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 None Of The Above

Answer: Conduction
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