If voltage is 12 V and current is 3 A, what is the resistance?

If voltage is 12 V and current is 3 A, what is the resistance?

• A. 2 ohms
• B. 3 ohms
• C. 4 ohms
• D. 6 ohms

Answer: (C)

Using Ohm’s Law, resistance is found by dividing voltage by current: R = V / I. With 12 volts and 3 amperes, R = 12 / 3 = 4 ohms. This value also fits the expected relationships: a smaller resistance would yield a larger current, and a larger resistance would yield a smaller current (for the same voltage). For example, 2 ohms would give 6 A, 3 ohms would give 4 A, and 6 ohms would give 2 A. Therefore, the resistance is 4 ohms.

Using Ohm’s Law, resistance is found by dividing voltage by current: R = V / I. With 12 volts and 3 amperes, R = 12 / 3 = 4 ohms. This value also fits the expected relationships: a smaller resistance would yield a larger current, and a larger resistance would yield a smaller current (for the same voltage). For example, 2 ohms would give 6 A, 3 ohms would give 4 A, and 6 ohms would give 2 A. Therefore, the resistance is 4 ohms.