If 17.32 V is applied across a 50 Ω resistor, how much power is dissipated in the resistor?

If 17.32 V is applied across a 50 Ω resistor, how much power is dissipated in the resistor?

• A. 6.0 watts
• B. 5.0 watts
• C. 1.0 watt
• D. 60 watts

Answer: (A)

Power in a resistor is determined by how much voltage is across it and its resistance, using P = V^2 / R. With 17.32 V across a 50 Ω resistor, P = (17.32)^2 / 50 ≈ 299.98 / 50 ≈ 6.0 watts. You can also verify by finding the current first: I = V / R ≈ 17.32 / 50 ≈ 0.346 A, then P = I^2 R ≈ (0.346)^2 × 50 ≈ 6.0 W. The other power values would correspond to different voltages (about 15.8 V for 5.0 W, about 7.1 V for 1.0 W, or about 54.8 V for 60 W), which aren’t what’s applied here.

Power in a resistor is determined by how much voltage is across it and its resistance, using P = V^2 / R. With 17.32 V across a 50 Ω resistor, P = (17.32)^2 / 50 ≈ 299.98 / 50 ≈ 6.0 watts. You can also verify by finding the current first: I = V / R ≈ 17.32 / 50 ≈ 0.346 A, then P = I^2 R ≈ (0.346)^2 × 50 ≈ 6.0 W. The other power values would correspond to different voltages (about 15.8 V for 5.0 W, about 7.1 V for 1.0 W, or about 54.8 V for 60 W), which aren’t what’s applied here.