Question

The current through the cell just after closing the switch S is :

• A. $\frac{\epsilon }{R}$
• B. $\frac{2\epsilon }{R}$
• C. $\frac{\epsilon }{3R}$
• D. $\frac{\epsilon }{2R}$

Answer 1

Answer: (D)

$\frac{\epsilon }{2R}$

At t=0, inductor can be treated as open circuit and hence circuit becomes as shown. By parallel, series calculations, the equivalent resistance of the circuit becomes R' = 2R. So, $I=\frac{ϵ}{2R}$