what is the electric potential at a distance of 9cm from 3nC?

Options

(a) 270V
(b) 3V
(c) 300V
(d) 30V

Correct Answer:

300V

Explanation:

Given, q = 3 nC = 3 × 10⁻⁹ C and r = 9 cm = 9 × 10⁻² m

We know that, potential due to point charge is given by V = (1 / 4πε₀) (q / r)

= (9 × 10⁹ × 3 × 10⁻⁹) / 9 × 10⁻² = 3 × 10²

⇒ Electric potential, V = 300 V