Question

When 2 × 10¹⁰ electrons are transferred from one conductor to another, a potential difference of 20 V appears between the conductors. Find the capacitance of the two conductors.

Answer 1

Data: n = 2 × 10¹⁰, e = 1.6 × 10⁻¹⁹ C, V = 20 V

Q = n × e

= (2 × 10¹⁰) × (1.6 × 10⁻¹⁹ C)

= 3.2 × 10⁻⁹ C 

∴ Capacitance, C = `Q/V`

= `(3.2 xx 10^(-9))/(20)`

= 1.6 × 10⁻¹⁰ F

= 160 pF