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An impedance of an LC series circuit is ______ (where X_L > X_C).

Asked in GSEB Board March 2022 · Impedance and phase angle

Answer: (2) Z = ω L - 1/(ω C)

Step-by-step solution

Idea: in a series LC circuit the same current I flows through both elements. V_L leads I by π/2 and V_C lags it by π/2, so V_L and V_C are exactly opposite.

Net voltage amplitude: V = V_L - V_C = I(X_L - X_C), positive because X_L > X_C.

So Z = V/I = X_L - X_C = ω L - 1/(ω C).

This is the general Z = √R² + (X_L - X_C)² with R = 0.

Why the other options are wrong

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