If I = 3 A and R = 2 Ω, what is the voltage E?

• A. 6 V
• B. 5 V
• C. 1.5 V
• D. 12 V

Answer: (B)

Voltage is found using Ohm’s law: E = I × R. With a current of 3 A through a 2 Ω resistor, E = 3 × 2 = 6 V. So the voltage is 6 volts. The other numbers don’t fit the given values, since they wouldn’t equal the product of 3 A and 2 Ω.