A 12 V source drives a 3 Ω resistor. What is the current through the resistor?

A 12 V source drives a 3 Ω resistor. What is the current through the resistor?

• A. 4 A
• B. 3 A
• C. 6 A
• D. 2 A

Answer: (A)

Current through a resistor is found using Ohm's law: I = V / R. With a 12 V source across a 3 Ω resistor, the current is 12 / 3 = 4 A. This aligns with how voltage pushes charge through resistance, and the units V/Ω equal amperes. The other numbers would require different voltage or resistance values (for example, 3 A would need 4 Ω, 6 A would need 2 Ω, and 2 A would need 6 Ω). So, given the setup, the current is 4 amperes.

Current through a resistor is found using Ohm's law: I = V / R. With a 12 V source across a 3 Ω resistor, the current is 12 / 3 = 4 A. This aligns with how voltage pushes charge through resistance, and the units V/Ω equal amperes. The other numbers would require different voltage or resistance values (for example, 3 A would need 4 Ω, 6 A would need 2 Ω, and 2 A would need 6 Ω). So, given the setup, the current is 4 amperes.