Q. If the capacity of a spherical conductor is $1\ picofarad,$ then its diameter, would be
A) $1.8 \times 10^{- 3}m$
B) $18 \times 10^{- 3}m$
C) $1.8 \times 10^{- 5}m$
D) $18 \times 10^{- 7}m$
Explanation
(b) $C = 4\pi\varepsilon_{0}R$
$R = \frac{C}{4\pi\varepsilon_{0}} = 9 \times 10^{9} \times 10^{- 12} = 9 \times 10^{- 3}m$
Diameter $= 2R = 2 \times 9 \times 10^{- 3} = 18 \times 10^{- 3}m$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.