Question

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

• A. $\frac{3\epsilon }{5R}$
• B. $\frac{\epsilon }{5R}$
• C. $\frac{3\epsilon }{R}$
• D. $\frac{\epsilon }{R}$

Answer 1

The correct option is A $\frac{3\epsilon }{5R}$

Long after closing the switch the p.d. across the inductor will zero.
therefore total resistance $=\frac{R\times 2R}{3R}+R=\frac{5R}{3}$
$i=\frac{\epsilon }{\left(\frac{5R}{3}\right)}$