The horizontally placed conductors of a single phase line

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The horizontally placed conductors of a single phase line operating at 50 Hz are having outside diameter of 1.6 cm, and the spacing between centers of the conductors is 6 m. The permittivity of free space is 8.854 × 10^–12 F/m. The capacitance to ground per kilometer of each line is

1. 4.2 × 10^–9F
2. 8.4 × 10^–9F
3. 4.2 × 10^–9F
4. 8.4 × 10^–9F

Correct Option: B

Capacitance to ground/m of each line

C =	2π∈₀					F/m
	In		D
			r

Where D is spacing between conductors and r is the radius of conductor.

⇒ C =	2π × 8.854 × 10^-12					F/m
	In		600
			0.8

= 8.4 × 10^-12 F/m
⇒ C = 8.4 × 10^-9 F/km