# Short Transmission Lines - MCQs with Answers

## Short Transmission Lines - MCQs with Answers

Q1. On what concept is electrically short, medium and long lines based on?

a. Nominal voltage of the line.
b. Physical length of the line.
c. Wavelength of the line.
d. Power transmitted over the line.

ANSWER: b. Physical length of the line.

Q2. The capacitance effect can be neglected in which among the transmission lines?

a. Short transmission lines.
b. Medium transmission lines.
c. Long transmission lines.
d. All of these.

ANSWER: a. Short transmission lines.

Q3. In the modelling of short length overhead transmission line, why is the line capacitance to ground not considered?

a. Equal to zero.
b. Finite but very small.
c. Finite but very large.
d. Infinite.

ANSWER: b. Finite but very small.

Q4. In a short transmission line, voltage regulation is zero when the power factor angle of the load at the receiving end side is equal to ____________.

a. tan-1 (X/R)
b. tan-1 (R/X)
c. tan-1 (X/Z)
d. tan-1 (R/Z)

ANSWER: b. tan-1 (R/X)

Q5. What is the power factor angle of the load for maximum voltage regulation?

a. tan-1 (X/R)
b. cos-1 (X/R)
c. tan-1 (R/X)
d. cos-1 (R/X)

ANSWER: a. tan-1 (X/R)

Q6. A single phase transmission line of impedance j0.8 ohm supplies a resistive load of 500 A at 300 V. The sending end power factor is

a. Unity
b. 0.8 lagging
d. 0.6 lagging

ANSWER: d. 0.6 lagging

Q7. For a short line if the receiving end voltage is equal to sending end voltage under loaded conditions

a. The sending end power factor is unity.
b. The receiving end power factor is unity.
c. The sending end power factor is leading.
d. The receiving end power factor is leading.

ANSWER: d. The receiving end power factor is leading.

Q8. What is the line length if a load of 15000 kW at a power factor 0.8 lagging can be delivered by a 3 phase transmission line having conductors each of resistance 1 Ω per kilometre? The voltage at the receiving end is to be 132kV and the loss is about 5%.

a. 40.13km
b. 37.18km
c. 42.38km
d. 35.87km