When voltage is increased across a fixed resistor, what happens to the current?

When voltage is increased across a fixed resistor, what happens to the current?

• A. Current increases
• B. Voltage remains the same
• C. Current decreases
• D. Power doubles

Answer: (A)

Ohm’s Law links voltage, current, and resistance. For a fixed resistor, the resistance stays constant, so the current changes directly with voltage: I = V / R. That means increasing the voltage across the resistor increases the current in direct proportion. If you double the voltage, you double the current; triple the voltage, triple the current, and so on. So the current increases when voltage goes up. As for the other ideas: the current wouldn’t stay the same or go down just from raising the voltage on a fixed resistor. Power isn’t simply doubled by increasing voltage; it grows with the square of the voltage (P = V^2 / R), so doubling voltage makes power increase by a factor of four.

Ohm’s Law links voltage, current, and resistance. For a fixed resistor, the resistance stays constant, so the current changes directly with voltage: I = V / R. That means increasing the voltage across the resistor increases the current in direct proportion. If you double the voltage, you double the current; triple the voltage, triple the current, and so on. So the current increases when voltage goes up.

As for the other ideas: the current wouldn’t stay the same or go down just from raising the voltage on a fixed resistor. Power isn’t simply doubled by increasing voltage; it grows with the square of the voltage (P = V^2 / R), so doubling voltage makes power increase by a factor of four.