Sag and Tension MCQ

1. Effect of increase in temperature in an overhead transmission line is

  1. to increase stress and length both
  2. to decrease stress and length both
  3. to decrease stress and increase length
  4. None of the above
Answer
Answer. c

2. If span length is doubled with no change in other factors, the sag of the line will become?

  1. 2 times
  2. 8 times
  3. 4 times
  4. 0.5 times
Answer
Answer. c

3. Find the approximate value of sag for a 66 kV line which has a span of 200 m between towers.

  1. 0.02 m
  2. 2 m
  3. 0.2 m
  4. 20 m
Answer
Answer. b

4. The effect of wind pressure is more predominant on

  1. Supporting tower
  2. Neutral wires
  3. Transmission lines
  4. insulators
Answer
Answer. a

5. The sag of a transmission line depends upon

  1. Weight of conductor and directly proportional to span length
  2. Weight of conductor and inversely proportional to span length
  3. Weight of conductor and directly proportional to the square of span length
  4. Weight of conductor and inversely proportional to the square of span length
Answer
Answer. c

6. Sag of the conductor’s between two poles can be determined by

  1. $S=\frac{WL^2}{T}$
  2. $S=\frac{WL^2}{2T}$
  3. $S=\frac{WL^2}{8T}$
  4. $S=\frac{WL^2}{16T}$
Answer
Answer. c

7. The sag of the conductors of a transmission line is 2.5 m when the span is 250 m. Now if the height of the supporting towers is increased by 2.5%, the sag will

  1. reduce by 25%
  2. increase by 25%
  3. reduce by 12.5%
  4. remain unchanged
Answer
Answer. d

8. Effect of temperature rise in overhead lines is to

  1. increase the sag and decrease the tension
  2. decrease the sag and increase the tension
  3. increase both the sag and tension
  4. decrease both the sag and tension
Answer
Answer. a

9. The sag of a transmission line conductor in summer is

  1. Less than that in winter
  2. More than that in winter
  3. Same as in winter
  4. None of these
Answer
Answer. b

10. The sag of a transmission line is least affected owing to

  1. weight of the conductor
  2. current through the conductor
  3. atmospheric temperature
  4. ice deposition on the conductor
Answer
Answer. b