An AC circuit has impedance Z = 5 Ω and RMS current I = 2 A. What is the RMS voltage across the circuit?

An AC circuit has impedance Z = 5 Ω and RMS current I = 2 A. What is the RMS voltage across the circuit?

• A. 5 V
• B. 15 V
• C. 10 V
• D. 20 V

Answer: (C)

In AC circuits, Ohm’s law uses impedance: V_rms = I_rms × |Z|. With a current of 2 A and an impedance magnitude of 5 Ω, the RMS voltage is 2 × 5 = 10 V. So the RMS voltage across the circuit is 10 volts. The other numbers would come from different I_rms or |Z| values (e.g., 5 V would come from 1 A or from a 2.5 Ω impedance, etc.), but with the given values the product gives 10 V.

In AC circuits, Ohm’s law uses impedance: V_rms = I_rms × |Z|. With a current of 2 A and an impedance magnitude of 5 Ω, the RMS voltage is 2 × 5 = 10 V. So the RMS voltage across the circuit is 10 volts. The other numbers would come from different I_rms or |Z| values (e.g., 5 V would come from 1 A or from a 2.5 Ω impedance, etc.), but with the given values the product gives 10 V.