Power System - Transmission Distribution - Electrical Engineering (MCQ) questions and answers

1)   What is the safety factor of an insulator?

a. Puncture strength * Flash over voltage
b. Puncture strength / Flash over voltage
c. Flash over voltage / Puncture strength
d. None of these
Answer  Explanation 

ANSWER: Puncture strength / Flash over voltage

Explanation:
No explanation is available for this question!


2)   Sag depends on which factor?

a. Span length
b. Weight of the conductors
c. Tension in the conductors
d. All of these
Answer  Explanation 

ANSWER: All of these

Explanation:
No explanation is available for this question!


3)   In a balanced 3 phase, 4 wire ac system the phase sequence is RYB. If the voltage of R phase = 230 ∠ 0° volts, then what will be the B phase?

a. 230 ∠ - 120°
b. 230 ∠ - 90°
c. 230 ∠ - 90°
d. 230 ∠ - 120°
Answer  Explanation 

ANSWER: 230 ∠ - 120°

Explanation:
No explanation is available for this question!


4)   The inductance of a power transmission line increases with

a. Decrease in line length
b. Increase in diameter of conductor
c. Increasing in spacing between the phase conductors
d. Increase in load current carried by the conductors
Answer  Explanation 

ANSWER: Increasing in spacing between the phase conductors

Explanation:
No explanation is available for this question!


5)   What is the horizontal spacing between phase conductors of 132 kV line?

a. 8 m.
b. 11 m.
c. 14 m.
d. 17 m.
Answer  Explanation 

ANSWER: 8 m.

Explanation:
No explanation is available for this question!


6)   What is the main drawback of overhead system over underground system?

a. Surge problem
b. High initial cost
c. Higher charging current
d. Underground system is more flexible than overhead system
Answer  Explanation 

ANSWER: Surge problem

Explanation:
No explanation is available for this question!


7)   What does the bedding on the cable consists of?

a. Jute strands
b. Hessian type
c. Paper tape compounded with a fibrous material
d. Any of these
Answer  Explanation 

ANSWER: Any of these

Explanation:
No explanation is available for this question!


8)   The capacitances of a 3 phase belted cable are 12.6 μ F  between the three cores bunched together and the lead sheath and 7.4 μ F between one core and the other two connected to sheath. What will be the charging current drawn by the cable when connected to a 66 kV supply?

a. 100 A
b. 99.3648 A
c. 105.236 A
d. 107.74 A
Answer  Explanation 

ANSWER: 107.74 A

Explanation:
No explanation is available for this question!


9)   A distribution system is shown in figure with load currents as marked. The two ends of the feeder are fed by voltage sources such that Vp = Vq = 3 V, the value of the voltage Vp for a minimum voltage of 220 V at any point along the feeder is

distribution system

a. 225.89 V
b. 222.89 V
c. 220.0 V
d. 228.58 V
Answer  Explanation 

ANSWER: 225.89 V

Explanation:
No explanation is available for this question!


10)   A 132 kV transmission line, with the weight of conductor = 680 kg/km, length of span = 260 m, ultimate strength = 3100 kg, safety factor =2. Calculate the height above ground at which the conductor should be supported. Ground clearance required is 10 m.

a. 10.7 m
b. 13.7 m
c. 20.83 m
d. 18.75 m
Answer  Explanation 

ANSWER: 13.7 m

Explanation:
No explanation is available for this question!


1 2 3 4 5 6 7 8 9 10 ...