Electrostatics Question 3
Question 3 - 24 January - Shift 2
The electric potential at the centre of two concentric half rings of radii $R_1$ and $R_2$, having same linear charge density $\lambda$ is
(1) $\frac{2 \lambda}{\epsilon_0}$
(2) $\frac{\lambda}{2 \epsilon_0}$
(3) $\frac{\lambda}{4 \epsilon_0}$
(4) $\frac{\lambda}{\epsilon_0}$
Show Answer
Answer: (2)
Solution:
Formula: Uniformly charged ring
Potential at centre
$ V=\frac{(\lambda \cdot \pi R_2)}{4 \pi \varepsilon_0 R_2}+\frac{(\lambda \cdot \pi R_1)}{4 \pi \varepsilon_0 R_1} $
$=\frac{\lambda}{2 \varepsilon_0}$