Question

The figure shows a circuit that contains four identical resistors with resistance $R=2.0\Omega$. Two identical inductors with inductance $L=2.0\text{mH}$ and an ideal battery with emf $E=9\text{V}$. The current$\left(i\right)$ just after the switch ${}^{\prime }{s}^{\prime }$ is closed will be:

• A. $9\text{A}$
• B. $3\text{A}$
• C. $2.25\text{A}$
• D. $3.37\text{A}$

Answer 1

The correct option is C $2.25\text{A}$

Just when switch ${}^{\prime }{s}^{\prime }$ is closed, inductor will behave like an infinite resistance.

Hence, the circuit will be like

Given:

$E=V=9\text{V}$
$R_{\text{eq}}=2+2=4\Omega$

From $V=IR$,

$I=\frac{V}{R}=\frac{9}{4}=2.25\text{A}$