Question

There are two conducting spheres of radius a and b (b$>$a) carrying equal and opposite charges. They are placed at a separation d($>>>$ a and b). The capacitance of system is?

• A. $\frac{4\pi {\epsilon }_0}{a-b-d}$
• B. $\frac{4\pi {\epsilon }_0}{\frac{1}{a}-\frac{1}{b}-\frac{1}{d}}$
• C. $\frac{4\pi {\epsilon }_0}{\frac{1}{a}+\frac{1}{b}-\frac{1}{d}}$
• D. $\frac{4\pi {\epsilon }_0}{\frac{1}{a}+\frac{1}{b}-\frac{2}{d}}$

Answer 1

The correct option is D $\frac{4\pi {\epsilon }_0}{\frac{1}{a}+\frac{1}{b}-\frac{2}{d}}$