1. more at leading pf
2. less at lagging pf
3. same at leading and lagging pf
4. more at lagging pf and less at leading pf
Answer: 1. more at leading pf
Explanation:
- The efficiency of a transmission line is determined by the ratio of power transmitted to the power supplied to the line. This ratio is known as the transmission line's power factor.
- When a transmission line operates at a lagging power factor, the voltage and current are out of phase, and the line consumes more power than it transmits. This results in a lower efficiency for the line.
- On the other hand, when a transmission line operates at a leading power factor, the voltage and current are in phase, and the line transmits more power than it consumes. This results in a higher efficiency for the line.
- Therefore, if a single-phase line delivers power at 11 kV at a distance of 15 km, the efficiency of the line will be higher when it operates at a leading power factor compared to when it operates at a lagging power factor.
