Question

The capacitance of a solid sphere of radius 18 cm is

• A. 40 pF
• B. 40 µF
• C. 20 pF
• D. 20 µF

Hint:

Use \( C = 4\pi \varepsilon_0 R \) for an isolated spherical conductor in vacuum or air.

Answer 1

The Correct Option is C

The capacitance of an isolated spherical conductor is given by: \[ C = 4\pi \varepsilon_0 R \] Given \( R = 18 \, \text{cm} = 0.18 \, \text{m} \) \[ C = 4\pi \times 8.85 \times 10^{-12} \times 0.18 \approx 2 \times 10^{-11} \, \text{F} = 20 \, \text{pF} \]