Question

The work done in carrying a charge q once round a circle of radius a with a charge Q at its centre is.

• A. $\frac{qQ}{4\pi\varepsilon_{0}a}$
• B. $\frac{qQ}{4\pi\varepsilon_{0}a^{2}}$
• C. $\frac{q}{4\pi\varepsilon_{0}a}$
• D. Zero (“kwU;)

Answer 1

Answer: (D)

Zero (“kwU;)

Answer 2

: The electric potential at any point on circle of radius a due to charge Q at its centre is

$V = \frac{1}{4\pi\varepsilon_{0}}\frac{Q}{a}$

It is an equipotential surface. Hence, work done in carrying a charge q round the circle is zero.