Question

Sketch a graph to show how the reactance of (i) a capacitor (ii) an inductor varies as a function of frequency.

Or

Draw the graphs showing variation of inductive reactance and capacitive reactance with frequency of applied a.c. source.

Answer 1

(i) Capacitive reactance

X_C = \(\frac{1}{\omega C} = \frac{1}{2\pi vC}\) 

i.e., X_C ∝ \(\frac{1}{v}\)

More the frequency, lesser the X_C and vice versa. The graph between X_C and v is as shown in Fig. 

(ii) Inductive reactance,

X_L = ωL

or X_L = 2πvL

or X_L ∝ v

i.e. inductive reactance is directly proportional to frequency.

The graph between XL and v is as shown in Fig.