Q 12-07-002NEETNEET 2025Top questionEasy
To an ac power supply of $220$ V at $50$ Hz, a resistor of $20\ \Omega$, a capacitor of reactance $25\ \Omega$ and an inductor of reactance $45\ \Omega$ are connected in series. The corresponding current in the circuit and the phase angle between the current and the voltage is, respectively -
Answer: (B) $7.8$ A and $45°$
Concept. $Z = \sqrt{R^2 + (X_L - X_C)^2}$, $I = \dfrac{V}{Z}$, $\tan\phi = \dfrac{X_L - X_C}{R}$.
Step 1. Impedance. $Z = \sqrt{20^2 + 20^2} = 20\sqrt2 \approx 28.3\ \Omega$.
Step 2. Current. $I = \dfrac{220}{28.3} \approx 7.8$ A.
Step 3. Phase. $\tan\phi = \dfrac{20}{20} = 1 \Rightarrow \phi = 45°$.
Answer. $7.8$ A and $45°$ (Option B).
Solution by Sreeraj P, M.Sc Physics