In an LR circuit with L = 200 mH and R = 50 Ω connected to a 24 V source, what is the steady-state current?

In an LR circuit with L = 200 mH and R = 50 Ω connected to a 24 V source, what is the steady-state current?

• A. I_ss = 0.24 A
• B. I_ss = 0.48 A
• C. I_ss = 0.96 A
• D. I_ss = 0.75 A

Answer: (B)

In steady-state with a DC source, the inductor acts as a short circuit, so it does not limit the current. The current is determined by the source voltage and the resistance: I_ss = V / R = 24 V / 50 Ω = 0.48 A. The inductance value affects only how quickly the current reaches that level; the time constant is τ = L / R = 0.2 H / 50 Ω = 0.004 s, so the current settles to 0.48 A after a few milliseconds.

In steady-state with a DC source, the inductor acts as a short circuit, so it does not limit the current. The current is determined by the source voltage and the resistance: I_ss = V / R = 24 V / 50 Ω = 0.48 A. The inductance value affects only how quickly the current reaches that level; the time constant is τ = L / R = 0.2 H / 50 Ω = 0.004 s, so the current settles to 0.48 A after a few milliseconds.