If resistance increases while voltage remains constant, what happens to current?

• A. Increase
• B. Decrease
• C. Stay the same
• D. Fluctuate

Answer: (B)

Current in a fixed-voltage circuit is governed by Ohm's law: I = V/R. If the voltage stays the same and the resistance increases, the current must decrease. For example, with 12 volts across a load, the current is 12/6 = 2 amps with a 6-ohm load, but if the resistance rises to 12 ohms, the current becomes 12/12 = 1 amp. So the current drops as resistance goes up. This also means the power drawn, P = V^2/R, decreases as resistance increases under a constant voltage.

The other options don’t fit because increasing current would require lower resistance, staying the same would require resistance unchanged, and fluctuating would imply changing resistance or voltage—neither happens when voltage is constant and resistance increases.