In a single-phase circuit with V = 230 V and R = 20 Ω, what is the current?

In a single-phase circuit with V = 230 V and R = 20 Ω, what is the current?

• A. 11.0 A
• B. 11.5 A
• C. 12.0 A
• D. 12.5 A

Answer: (B)

This question tests using Ohm's law in a simple resistive circuit: current equals voltage divided by resistance. With 230 V across a 20 Ω resistor, the current is I = V / R = 230 ÷ 20 = 11.5 A. So the current is 11.5 amperes. In a pure resistive circuit, power would be P = V × I = 230 × 11.5 ≈ 2645 W. If there were reactance, you’d use impedance instead of just resistance, but here the calculation is straightforward.

This question tests using Ohm's law in a simple resistive circuit: current equals voltage divided by resistance. With 230 V across a 20 Ω resistor, the current is I = V / R = 230 ÷ 20 = 11.5 A. So the current is 11.5 amperes. In a pure resistive circuit, power would be P = V × I = 230 × 11.5 ≈ 2645 W. If there were reactance, you’d use impedance instead of just resistance, but here the calculation is straightforward.