JEE Physics 2023 Question with Solution

Given: The graph shows variation of impedance with frequency.

Find: Which physical quantities are represented by curve $A$ and curve $B$.

For a pure inductor,

$$X_L = \omega L$$

so inductive reactance increases with frequency.

For a pure capacitor,

$$X_C = \frac{1}{\omega C}$$

so capacitive reactance decreases with frequency.

Thus, the curve that decreases with frequency represents $X_C$, and the curve that increases with frequency represents $X_L$.

Therefore, $A = X_C$ and $B = X_L$. The correct option is D.