ELECTRICAL ENGINEERING MCQ_22

Q.341 The steady state stability of the power system is most effected by
A. transmission line reactance
B. Voltage at generator bus
C. stability of generator
D. power factor of the load
Ans.: A

Q.342 In case of HVDC transmission there is__
A. Charging current but no skin effect
B. no charging current no skin effect
C. no charging current but skin effect
D. both charging effect and skin effect
Ans.: B

Q.343 HVDC transmission is preferred to EHV AC because
A. Its terminal equipment are inexpensive
B. VAR compensation is not required in it
C. System stability can be improved
D. Harmonic problem is avoided
Ans.: C

Q.344 The insulation strength of an EHV transmission line is mainly governed by
A. load power factor
B. Switching over voltage
C. Harmonics
D. Corona
Ans.: B

Q.345 Earth wire on EHV overhead transmission line is provided to protect the lines against
A. lighting surge
B. switching surge
C. excessive fault voltage
D. corona effect
Ans.: A

Q.346 Shunt compensation in EHV line is restored to
A. Improve the stability
B. Reduce the fault level
C. increase line impedance
D. improve voltage profile
Ans.: D

Q.347 Switching surge are
A. high voltage DCs
B. high voltage ACs
C. short duration transient voltage
D. power frequency voltage
Ans.: C

Q.348 during the insulation co-ordination in the substation, the lowest insulation strength is at
A. CTs and PTs
B. transformer
C. circuit breaker
D. bus bar
Ans.: B

Q.349 Current chopping phenomenon is related to
A. resistance switching
B. capacitance switching
C. small inductive current
D. asymmetrical current
Ans.: C

Q.350 The breaking capacity of a CB is usually expressed in terms of
A. amperes
B. volts
C. MW
D. MVA
Ans.: D

Q.351 Merz-Price protection is employed for protection of
A. motor
B. circuit breaker
C. transmission lines
D. alternators
Ans.: D

Q.352 In substations for making and breaking of load current
A. Isolators are used
B. circuit breakers are used
C. load interruption switches are used
D. relays are used
Ans.: C

Q.353 Which of the following is not function of substation batteries?
A. operating automatic control circuits
B. providing supply to the excitation system
C. emergency lighting circuits
D. operating protective relay system
Ans.: B

Q.354 Shunt capacitors in a substation
A. consumes lagging VAR
B. delivers lagging VAR
C. consume active power
D. deliver active power
Ans.: B

Q.355 In a given current transformer, if permissible current error rated primary current is 5% the CT is suitable for
A. protective purpose
B. measuring purpose
C. both measuring and protection
D. as power transformer
Ans.: B