If a 500 Ω resistor has 1.5 mA through it, what is the voltage across it?

If a 500 Ω resistor has 1.5 mA through it, what is the voltage across it?

• A. 0.75 V
• B. 0.075 V
• C. 7.5 V
• D. 75 V

Answer: (A)

Voltage across a resistor comes from multiplying the current by the resistance: V = I × R. Here, the current is 1.5 mA, which is 0.0015 A, and the resistance is 500 Ω. Multiply: 0.0015 A × 500 Ω = 0.75 V. So the voltage is 0.75 volts. If you keep the current in milliamps, 1.5 mA × 500 Ω equals 750 mV, which is the same value expressed in millivolts. The other numbers come from not converting units or decimal placement.

Voltage across a resistor comes from multiplying the current by the resistance: V = I × R. Here, the current is 1.5 mA, which is 0.0015 A, and the resistance is 500 Ω. Multiply: 0.0015 A × 500 Ω = 0.75 V. So the voltage is 0.75 volts. If you keep the current in milliamps, 1.5 mA × 500 Ω equals 750 mV, which is the same value expressed in millivolts. The other numbers come from not converting units or decimal placement.