If voltage doubles while resistance remains the same, what happens to current?

If voltage doubles while resistance remains the same, what happens to current?

• A. Current stays the same
• B. Current decreases
• C. Current doubles
• D. Current goes to zero

Answer: (C)

Ohm's law shows that current is proportional to voltage when the resistance is fixed: I = V / R. If the resistance doesn’t change and you double the voltage, the current must double as well, because you’re dividing the doubled voltage by the same resistance. For example, with R = 10 ohms, a voltage of 5 V gives I = 0.5 A; increasing V to 10 V gives I = 1 A. Since current scales directly with voltage at a constant resistance, doubling the voltage doubles the current. The other possibilities would require changing the resistance or removing the voltage, which isn’t indicated here.

Ohm's law shows that current is proportional to voltage when the resistance is fixed: I = V / R. If the resistance doesn’t change and you double the voltage, the current must double as well, because you’re dividing the doubled voltage by the same resistance. For example, with R = 10 ohms, a voltage of 5 V gives I = 0.5 A; increasing V to 10 V gives I = 1 A. Since current scales directly with voltage at a constant resistance, doubling the voltage doubles the current. The other possibilities would require changing the resistance or removing the voltage, which isn’t indicated here.