Explore topic-wise MCQs in Electrical Engineering Questions.

This section includes 192 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering Questions knowledge and support exam preparation. Choose a topic below to get started.

151.

For which of the following protection from negative sequence currents is provided ?
A. Generators
B. Motors
C. Transmission line
D. Transformers
Answer» B. Motors
Discussion
152.

When a wave propagates on a transmission line, it suffers reflection several times at_____________?
A. tapping
B. load end
C. sending end
D. sending and other end
E. all of the above
Answer» E. all of the above
Discussion
153.

The reflection co-efficient at the open circuited end of a transmission line___________?
A. zero
B. infinity
C. unity
D. none of the above
Answer» D. none of the above
Discussion
154.

H.R.C. fuses provide best protection against________________?
A. overload
B. reverse current
C. open-circuits
D. short-circuits
Answer» E.
Discussion
155.

The contacts of high voltage switches used in power system are submerged in oil. The main purpose of the oil is to______________?
A. lubricate the contacts
B. insulate the contacts from switch body
C. extinguish the arc
D. all of the above
E. none of the above
Answer» D. all of the above
Discussion
156.

To protect most of the electrical equipment handling low power, the types of relays used are______________?
A. thermocouple
B. electronic and bimetallic
C. both (A) and (B)
D. none of the above
Answer» D. none of the above
Discussion
157.

Which of the following is the least expensive protection for overcurrent is low voltage system ?
A. Rewireable fuse
B. Isolator
C. Oil circuit breaker
D. Air break circuit breaker
E. None of the above
Answer» B. Isolator
Discussion
158.

The delay fuses are used for the protection of ___________?
A. motors
B. power outlet circuits
C. fluorescent lamps
D. light circuits
Answer» B. power outlet circuits
Discussion
159.

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» B. Unity
Discussion
160.

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
Answer» B. 0.001 sec
Discussion
161.

Short-circuit currents are due to_______________?
A. single phase to ground faults
B. phase to phase faults
C. two phase to ground faults
D. three phase faults
E. any of these
Answer» F.
Discussion
162.

For cost and safety, the outdoor substations are installed for voltages above_________________?
A. 11 kV
B. 33 kV
C. 60kV
D. 110kV
Answer» C. 60kV
Discussion
163.

A.C. network analyser is used to solve problems of_______________?
A. load flow
B. load flow and short-circuit
C. load flow and stability
D. load flow, short-circuit and stability
E. none of the above
Answer» E. none of the above
Discussion
164.

To reduce short circuit fault currents are used_____________?
A. reactors
B. resistors
C. capacitors
D. none of the above
Answer» B. resistors
Discussion
165.

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
Answer» C. Vacuum circuit breakers
Discussion
166.

transmission line has reflection coefficient as one?
A. Open circuit
B. Short-circuit
C. Long
D. None of the above
Answer» B. Short-circuit
Discussion
167.

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
Answer» E. none of the above
Discussion
168.

The single phasing relays are used for the protection of_____________?
A. single phase motors only
B. two phase motors only
C. two single phase motors running in parallel
D. three phase motors
Answer» E.
Discussion
169.

Arc in a circuit breaker is interrupted at___________?
A. zero current
B. maximum current
C. minimum voltage
D. maximum voltage
Answer» B. maximum current
Discussion
170.

The fuse rating is expressed in terms of_____________?
A. current
B. voltage
C. VAR
D. kVA
Answer» B. voltage
Discussion
171.

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
Answer» C. 5 to 20 sec
Discussion
172.

A _________ is used to measure the stator % winding temperature of the generator?
A. thermocouple
B. pyrometer
C. resistance thermometer
D. thermometer
Answer» D. thermometer
Discussion
173.

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» B. Relays
Discussion
174.

Distance relays are generally_____________?
A. split-phase relays
B. reactance relays
C. impedance relays
D. none of the above
Answer» E.
Discussion
175.

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
Answer» D. All of the above
Discussion
176.

A balanced 3-phase system consists of_______________?
A. zero sequence currents only
B. positive sequence currents only
C. negative and zero sequence currents
D. zero, negative and positive sequence currents
Answer» C. negative and zero sequence currents
Discussion
177.

The information to the circuit breaker under fault conditions is provided by____________?
A. relay
B. rewirable fuse
C. H.R.C. only
D. all of the above
Answer» B. rewirable fuse
Discussion
178.

On which of the following effects of electric current a fuse operates ?
A. Photoelectric effect
B. Electrostatic effect
C. Heating effect
D. Magnetic effect
Answer» D. Magnetic effect
Discussion
179.

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. reducing the excitation of machines
E. none of the above
Answer» B. connecting lines in series
Discussion
180.

The power loss is an important factor for the design of_______________?
A. transmission line
B. motor
C. generator
D. feeder
Answer» B. motor
Discussion
181.

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» B. low melting point and -low specific resistance
Discussion
182.

A fuse is connected_______________?
A. in series with circuit
B. in parallel with circuit
C. either in series or in parallel with circuit
D. none of the above
Answer» B. in parallel with circuit
Discussion
183.

For which among the following the current ratings are not required?
A. Circuit breakers
B. Relays
C. Isolators
D. Load break switch
Answer» D. Load break switch
Discussion
184.

Series capacitors are used to_________________?
A. compensate for line inductive reactance
B. compensate for line capacitive reactance
C. improve line voltage
D. none of the above
Answer» B. compensate for line capacitive reactance
Discussion
185.

H.R.C. fuse, as compared to a rewirable fuse, has_________________?
A. no ageing effect
B. high speed of operation
C. high rupturing capacity
D. all of the above
Answer» E.
Discussion
186.

An isolator is installed_____________?
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
Answer» E.
Discussion
187.

What is the making to breaking current ratio for an extra high voltage circuit breaker?
A. More than 1
B. Equal to 1
C. Less than 1
D. A negative value
Answer» B. Equal to 1
Discussion
188.

Why is an isolator installed?
A. To isolate one portion of the circuit from another
B. As an substitute for the circuit breaker
C. It used on either sides of the circuit breaker
D. Both (a) and (c)
E. None of these
Answer» B. As an substitute for the circuit breaker
Discussion
189.

Why are the isolators used?
A. Break abnormal current
B. Making under fault conditions
C. Breaking the circuit under no load condition
D. None of the above
Answer» D. None of the above
Discussion
190.

The isolators used in the transmission lines are capable of breaking
A. Fault current
B. No current
C. Charging current
D. Load current
Answer» D. Load current
Discussion
191.

Arc in a circuit behaves as_______________?
A. a capackive 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
Answer» E.
Discussion
192.

Thermal circuit breaker has____________?
A. delayed trip action
B. instantaneous trip action
C. both of the above
D. none of the above
Answer» B. instantaneous trip action
Discussion