Alternating Current - Result Question 14

14. Figure shows a circuit that contains three identical resistors with resistance $R=9.0 \Omega$ each, two identical inductors with inductance $L=2.0$ $mH$ each, and an ideal battery with emf $\varepsilon=18 V$. The current ’ $i$ ’ through the battery just after the switch closed is

[2017]

(a) $0.2 A$

(b) $2 A$

(c) 0

(d) $2 mA$

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Answer:

Correct Answer: 14. (b)

Solution:

  1. (b)

At $t=0$, no current flows through $R_1$ and $R_3$

Current through battery just after the switch closed is

$ i=\frac{\varepsilon}{R_2}=\frac{18}{9}=2 A $