Question

A source voltage of 100 V dc is applied across a RLC series circuit. Under steady-state conditions, voltages across each element is

• A. \( V_R = 100V, V_L = 0, V_C = 0 \)
• B. \( V_R = 100V, V_L = -100V, V_C = 100V \)
• C. \( V_R = 0, V_L = 100V, V_C = -100V \)
• D. \( V_R = 0, V_L = 0, V_C = -100V \)

Hint:

Under DC steady-state, inductor behaves as a short and capacitor as an open. Use this to quickly deduce element voltages.

Answer 1

The Correct Option is D

In steady-state for a DC source:
- Inductor acts as a short circuit: \( V_L = 0 \)
- Capacitor acts as an open circuit: voltage across capacitor equals the source voltage with opposite polarity, i.e., \( V_C = -100V \)
- No current flows in the circuit, so \( V_R = 0 \) Thus: \[ V_R = 0, V_L = 0, V_C = -100V \]