In the circuit shown below, the key K is closed at t=0 . The current through the battery is

  • Option 1)

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

  • Option 2)

    \frac{VR_{1}R_{2}}{\sqrt{R_{1}^{2}+R_{2}^{2}}}\, at\; t=0\; and\; \frac{V}{R_{2}}\, at\; t=\infty

  • Option 3)

    \frac{V}{R_{2}}\, \, at\,t=0\; and\; \, \frac{V(R_{1}+R_{2})}{R_{1}R_{2}}at\; t=\infty

  • Option 4)

    \frac{V}{R_{2}}at\; t=0\; and\;\frac{VR_{1}R_{2}}{\sqrt{R_{1}^{2}+R_{2}^{2}}}\, at\; t=\infty

 

Answers (1)

As we learnt in 

Self Inductance -

An emf is induced in the coil or the circuit which oppose the change that causes it. Which is also known back  emf.

- wherein

 

 at t=0, there is no current through inductor

\therefore I=0

as t \rightarrow \infty

I=\frac{V}{R_{eq}}

=\frac{V/R_{1}R_2}{R_1+R_2}

=\frac{V(R_1+R_2)}{R_1+R_2}


Option 1)

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

Incorrect option

Option 2)

\frac{VR_{1}R_{2}}{\sqrt{R_{1}^{2}+R_{2}^{2}}}\, at\; t=0\; and\; \frac{V}{R_{2}}\, at\; t=\infty

Incorrect option

Option 3)

\frac{V}{R_{2}}\, \, at\,t=0\; and\; \, \frac{V(R_{1}+R_{2})}{R_{1}R_{2}}at\; t=\infty

Correct option

Option 4)

\frac{V}{R_{2}}at\; t=0\; and\;\frac{VR_{1}R_{2}}{\sqrt{R_{1}^{2}+R_{2}^{2}}}\, at\; t=\infty

Incorrect option

Preparation Products

JEE Main Rank Booster 2021

This course will help student to be better prepared and study in the right direction for JEE Main..

₹ 13999/- ₹ 9999/-
Buy Now
Knockout JEE Main April 2021 (Subscription)

An exhaustive E-learning program for the complete preparation of JEE Main..

₹ 6999/- ₹ 5/-
Buy Now
Knockout JEE Main April 2021

An exhaustive E-learning program for the complete preparation of JEE Main..

₹ 22999/- ₹ 14999/-
Buy Now
Knockout JEE Main April 2022

An exhaustive E-learning program for the complete preparation of JEE Main..

₹ 34999/- ₹ 24999/-
Buy Now
Knockout JEE Main January 2022

An exhaustive E-learning program for the complete preparation of JEE Main..

₹ 34999/- ₹ 24999/-
Buy Now
Exams
Articles
Questions