Electromagnetic Induction and Alternating Current 4 Question 8
8. In the circuit shown here, the point $C$ is kept connected to point $A$ till the current flowing through the circuit becomes constant. Afterward, suddenly point $C$ is disconnected from point $A$ and connected to point $B$ at time $t=0$. Ratio of the voltage across resistance and the inductor at $t=L / R$ will be equal to
(2014 Main)
(a) $\frac{e}{1-e}$
(b) 1
(c) -1
(d) $\frac{1-e}{e}$
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Answer:
Correct Answer: 8. (c)
Solution:
- After connecting $C$ to $B$ hanging the switch, the circuit will act like an $L-R$ discharging circuit.
Applying Kirchhoff’s loop
equation,
$$ V _R+V _L=0 \Rightarrow V _R=-V _L \Rightarrow \frac{V _R}{V _L}=-1 $$
