ELECTRICAL ENGIENERING MCQ_17

Q.266 IF the voltage is increased by n times, the size of the conductor would
A. increase by n times

B. reduce by 1/n times
C. increase by n^2 times

D. reduce by 1/n^2 times
Ans.: D

Q.267 The semiconductors and insulating material are having ____ temperature coefficient of resistance. Therefore, the resistance of semiconductors and insulators ___ with rise in temperature.
A. positive, decrease

B. negative, increase
C. negative, decrease

D. positive, increase
Ans.: A

Q.268 What type of magnetic behavior is observed in a type-I superconductor?
A. perfect diamagnetism

B. perfect paramagnetism
C. perfect ferromagnetism

D. perfect ferringnetism
Ans.: A

Q.269 Shunt strip are usually made of
A. copper

B. aluminium

C. silver

D. manganin
Ans.: D

Q.270 In houses the illumination is in the range of
A. 2-5 lumens/watt

B. 10-20 lumens/watt
C. 35-45 lumens/watt

D. 60-65 lumens/watt
Ans.: D

Q.271 The transient stability limit of a copper system can be appreciably increased by introducing
A. series inductance

B. shunt inductance
C. series capacitance

D. shunt capacitance
Ans.: C

Q.272 If the length of a wire of resistance R is uniformly stretched to n times its original value, its new resistance is
A. nR

B. R/n

C. n2R

D. R/n2
Ans.: C

Q.273 In an a.c series RLC circuit, the voltage across R and L is 20V, voltage across L and C is 9 v and voltage across RLC is 15V. What is the voltage across C?
A. 7V

B. 12V

C. 16V

D. 21V
Ans.: A

Q.274 In a bulk oil circuit breaker, the oil actually used for arc extinction is about
A. 60 % of total

B. 40% of total

C. 90% of total

D. 10% of total
Ans.: D

Q.275 When a line to ground fault occurs, the current in the fault phase is 100A. The zero-sequence current in this case is
A. 33.33 A

B. zero

C. 66.6A

D. 100A
Ans.: A

Q.276 Under dry conditions, the resistance offered by the human body may be as high as
A. 200Ω

B. 100Ω

C. 100000Ω

D. 250Ω
Ans.: C

Q.277 An inductive circuit draws a line current of 10A. If the reactive component of line current is 6A, then power factor of the circuit is
A. 0.6 lagging

B. 0.8 lagging

C. 0.5 lagging

D. none of the above
Ans.: B

Q.278 A charge of 4.8 x 10^5 C passes through a solution of copper suphate. The number of Cu++ ions liberated from the electrolyte is
A. 2 x 10^12

B. 1.25 x 10^22

C. 3×10^19

D. 1.5 x 10^24
Ans.: D

Q.279 The transformer has a turns ratio of 4:1. The resistance of the HV winding is 8 ohms and that of the LV winding is 1 ohm. The total resistance on HV side in ohms is
A. 9

B. 8.25

C. 24

D. 9.5
Ans.: C

Q.280 Two wires are of equal length. One is bent into square loop and the other circular loop. They are suspended I uniform magnetic field and the same current us passed through them. The torque will be
A. equal in two cases

B. more on square loop
C. more on circular loop

D. data incomplete
Ans.: C