Question

In the circuit shown here, the point $C$ is kept connected to point $A$ till the current flowing through the circuit become constant. Afterward, suddenly point $C$ disconnected from point $A$ and connected to point $B$ at time $t=0$. Ratio of the voltage across resistance and the inductor at $t=\frac{L}{R}$ will be equal to

• A. $\frac{1-e}{e}$
• B. $1$
• C. $\frac{e}{1-e}$
• D. $-1$

Answer 1

The correct option is D $-1$

After connecting $C$ to $B$ (hanging the switch), the circuit will act like an L R discharging circuit.


Applying Kirchoff loop equation.
$V_R+V_L=0$
$\Rightarrow V_R=-V_L$
So $\frac{V_R}{V_L}=-1$

Hence, option $C$ is correct.