Topic: Network Theory
A step voltage of 1 V applied to the circuit at t = 0. The current through the resistor R just after t = 0 and at steady state are:
- A. 100 mA, 50 mA
- B. 50 mA, 50 mA
- C. 100 mA, 100 mA
- D. 75 mA, 75 mA
Answer: A. 100 mA, 50 mA
Explanation: At t = 0+, the uncharged capacitor acts as a short circuit (v_c = 0 V), making the equivalent resistance 10 Ω, so I_R(0+) = 1 V / 10 Ω = 100 mA. At steady state (t -> ∞), the capacitor acts as an open circuit, giving an equivalent resistance of 20 Ω, so I_R(steady state) = 1 V / 20 Ω = 50 mA.