Question

The capacitance of an isolated conducting sphere of radius 18 cm placed in vacuum will be _____pF. (Answer upto 2 decimal places)

• A. 20

Answer 1

The correct option is A 20
Given radius of sphere, r = 18 cm

Capacitance,
C = $4\pi ϵrwhereϵ={ϵ}_0$ $(\because vacuummedium)$

$C=4\pi \times \frac{{10}^{-9}}{36\pi }\times 18\times {10}^{-2}=20pF$