In AC circuits, the relation that holds is $Z=\frac{E_v}{I_v}$ where.

A. $Z=\sqrt{R^2+X_L^2}$ in case of a.c. circuit containing R and L in series.
B. $Z=\sqrt{R^2+X_C^2}$ in case of a.c. circuit containing R and C in series.
C. $Z=X_L-X_C$, in case of a.c. circuit containing L and C in series.
D. $Z=\sqrt{R^2+(X_L-X_C)^2}$ in case of ac circuit containing R, L and C in series

Choose the correct answer from the options given below:

A, B, C, D only

The correct answer is Option (4) → A, B, C, D only

Impedance of an LCR circuit is,

$Z=\sqrt{R^2+(X_L-X_C)^2}$

⇒ RL Series

$Z=\sqrt{R^2+{X_L}^2}$

⇒ RC Series

$Z=\sqrt{R^2+{X_C}^2}$

⇒ RL Series

$Z=X_L-X_C$