In a circuit containing a battery of emf V , a resistor R_2 in series with an inductor L and resistor R_1 in parallel, the key K is closed at t = 0 . - Physics MCQ AIEEE 2026 | ExamTest.live

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In a circuit containing a battery of emf V, a resistor R_{2} in series with an inductor L and resistor R_{1} in parallel, the key K is closed at t = 0 . The current through the battery is:

A $\frac{V ( R _{1} + R _{2} )}{R _{1} R _{2}} at t = 0 and \frac{V}{R _{2}} at t = \infty$
B $\frac{V}{R _{2}} at t = 0 and \frac{V ( R _{1} + R _{2} )}{R _{1} R _{2}} at t = \infty$
C $\frac{V}{R _{2}} at t = 0 and \frac{V R _{1} R _{2}}{R _{1} + R _{2}} at t = \infty$
D $\frac{V R _{1} R _{2}}{R _{1} + R _{2}} at t = 0 and \frac{V}{R _{2}} at t = \infty$

Solution & Step-by-step Explanation

At t = 0, an inductor acts as an open circuit (infinite resistance).Current only flows through R_{2} . I = \frac{V}{R _{2}} .At t = \infty, an inductor acts as a short circuit (zero resistance).The circuit effectively has R_{1} and R_{2} in parallel. R_{e q} = \frac{R _{1} R _{2}}{R _{1} + R _{2}} .Current I = \frac{V}{R _{e q}} = \frac{V ( R _{1} + R _{2} )}{R _{1} R _{2}} .

Try it yourself before checking the explanation above.

In a circuit containing a battery of emf V, a resistor R_{2} in series with an inductor L and resistor R_{1} in parallel, the key K is closed at t = 0 . The current through the battery is:

\frac{V ( R _{1} + R _{2} )}{R _{1} R _{2}} at t = 0 and \frac{V}{R _{2}} at t = \infty

\frac{V}{R _{2}} at t = 0 and \frac{V ( R _{1} + R _{2} )}{R _{1} R _{2}} at t = \infty

\frac{V}{R _{2}} at t = 0 and \frac{V R _{1} R _{2}}{R _{1} + R _{2}} at t = \infty

\frac{V R _{1} R _{2}}{R _{1} + R _{2}} at t = 0 and \frac{V}{R _{2}} at t = \infty

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