ELECTRICAL ENGINEERING MCQ_16

Q.251 The operating time of a fuse is about
A. 0.002 sec.

B. 1 sec.

C. 0.8 sec

D. 1.5 sec.
Ans.: A

Q.252 A 5° C rise in temperature is observed in a conductor by passing a current. When the current is doubled, the rise in temperature in temperature will be
A. 10° C

B. 12° C

C. 16° C

D. 20° C
Ans.: D

Q.253 If the back emf in d.c motor vanishes suddenly, the motor will
A. run at very high speed

B. run at very low speed
C. have winding burnt

D. not run at all
Ans.: C

Q.254 A distribution transformer is rated at 100 KVA. The maximum active power that it can supply is
A. 200 KW

B. 75 KW

C. 155 KW

D. 100 KW
Ans.: D

Q.255 A 2 KVA transformer has iron loss of 150w and full load copper loss of 250 w. The maximum efficiency of the transformer would be occurs when the total loss is
A. 300W

B. 400 W

C. 500W

D. 275 W
Ans.: A

Q.256 The two-part tariff is used for
A. domestic consumers

B. commercial consumers
C. agricultural consumers

D. industrial consumers
Ans.: D

Q.257 In which part of the thermal power plant, the steam pressure is less than that of atmosphere?
A. Boiler

B. Turbine

C. Condenser

D. Super-heater
Ans.: C

Q.258 Stray losses consist of
A. magnetic and mechanical losses

B. magnetic and copper losses
C. mechanical and copper losses

D. none of the above
Ans.: A

Q.259 If 3 MW power is to be transmitted over a distance of 20 kms., the desirable transmission voltage will be
A. 11 Kv

B. 33 KV

C.66 KV

D. 3.3KV
Ans.: C

Q.260 Nuclear reactors utilize the process of
A. fusion

B. fission

C. both fusion and fission

D. none of the above
Ans.: B

Q.261 In a two phase generator, the electrical displacement between the two phases or winding is___ electrical degrees.
A. 120

B. 90

C. 180

D. none of the above
Ans.: B

Q.262 Ampere hour is the unit of
A. electric current

B. electric charge

C. electric energy

D. electric power
Ans.: B

Q.263 An induction motor and synchronous motor are connected to a common feeder line. To operate the feeder line at unity pf, the synchronous motor should be
A. under excited

B. over excited
C. normally excited

D. disconnected from the common terminals
Ans.: B

Q.264 Poles of dc machine are often laminated to
A. reduce pulsation loss

B. reduce armature reaction
C. reduce iron weight

D. dissipate more heat
Ans.: A

Q.265 Sky appears blue because of
A. refraction

B. reflection

C. radiation

D. scattering of light dust particles
Ans.: D