Question

The radius of a sphere of capacity 1 microfarad in the air is ______

Options

• 9 km

• 0.9 km

• 0.09 km

• 9 m

Answer 1

The radius of a sphere of capacity 1 microfarad in the air is 9 km.

Explanation:

For a sphere of given capacity

C = 4πε₀r

r = `"C"/(4piε_0) = 9 xx 10^9 xx 1 xx 10^-6`

∴ r = `9 xx 10^3`m = 9 km