Understand Series Resonance Condition

In an RLC series resonance circuit, the inductive reactance ($X_L$) and capacitive reactance ($X_C$) cancel each other out, such that the net reactance is zero ($X_L - X_C = 0$).

$Z = R + j(X_L - X_C) = R$

Identify Impedance

At resonance, the total impedance ($Z$) of the circuit is equal to the resistance ($R$). Given $R = 50 \Omega$, the impedance is $50 \Omega$.

$Z = 50 \Omega$

Calculate Current

Using Ohm's Law for AC circuits at resonance, divide the source voltage by the resistance.

$I = \frac{200}{50} = 4A$