Question:
$\text{Alternating voltage } V = V_0 \sin \omega t \text{ is applied to a circuit containing some elements in series.}$ $\text{Match the values of current in Column I with the possible elements connected in the circuit in Column II.}$ $\begin{array}{|c|c|} \hline \text{Column-I} & \text{Column-II} \\ \hline (A) \ I = I_0 \sin \omega t & (P) \ \text{only inductor circuit} \\ (B) \ I = -I_0 \cos \omega t & (Q) \ \text{may be } C-R \text{ circuit} \\ (C) \ I = I_0 \sin \left( \omega t + \frac{\pi}{4} \right) & (R) \ \text{may be } L-R \text{ circuit} \\ (D) \ I = I_0 \sin \left( \omega t - \frac{\pi}{4} \right) & (S) \ \text{only resistance circuit} \\ \hline \end{array}$
Solution:
$\text{Hint: Recall the different types of AC circuits.}$ $\text{Step: Find the correct match.}$ $(A) \ \text{In a purely resistive circuit the phase difference between the current and voltage is zero. Therefore, } V = V_0 \sin \omega t \text{ and } I = I_0 \sin \omega t \text{ represents the purely resistive circuit.}$ $(B) \ \text{In a purely inductive circuit the current lags the voltage by } \frac{\pi}{2}. \text{ Therefore, } V = V_0 \sin \omega t \text{ and } I = -I_0 \cos \omega t \text{ represents the purely inductive circuit.}$ $(C) \ \text{For } V = V_0 \sin \omega t \text{ and } I = I_0 \sin \left( \omega t + \frac{\pi}{4} \right), \text{ the current is leading but the phase is less than } \frac{\pi}{2}. \text{ Therefore, the given circuit may be } C-R \text{ circuit.}$ $(D) \ \text{For } V = V_0 \sin \omega t \text{ and } I = I_0 \sin \left( \omega t - \frac{\pi}{4} \right), \text{ the current is lagging but the phase is less than } \frac{\pi}{2}. \text{ Therefore, the given circuit may be } L-R \text{ circuit.}$ $\text{Therefore, the correct match is } A \rightarrow S; \ B \rightarrow P; \ C \rightarrow Q; \ D \rightarrow R. \text{ Hence, option (3) is the correct answer.}$