Question

What is the capacitance of a 1.0" diameter steel ball-bearing? A. 1.4 pF B. 14 pF C. 140 pF D. Zero, since there is only one conducting surface Capacitance is not defined for a single conducting surface E.

Answer 1

option A

Step-by-step explanation:

steel in a conducting ball of diameter

2 r = 1 '' = 2.54 cm = 2.54 × 10⁻² m

Potential due to conducting steel ball

`V = (1)/(4\pi \epsilon_0)(q)/(r)`

`(q)/(V) = {4\pi \epsilon_0}{r}`

`C = (1)/(9* 10^9)*(2.54* 10^(-2))/(2)`

C = 0.1411 × 10⁻¹¹ Farad

C = 1.411 × 10⁻¹² Farad

C = 1.4 pF

Hence, correct answer is option A