To increase the current through a resistor, which action would be effective?

• A. Increase the resistance
• B. Decrease the voltage
• C. Increase the voltage
• D. Increase the room temperature

Answer: (C)

The relationship between current, voltage, and resistance is described by I = V / R. For a resistor with fixed resistance, increasing the voltage raises the current proportionally, because more voltage pushes more charge through the same amount of resistance. So turning up the voltage effectively increases current.

Increasing the resistance would reduce current, and decreasing the voltage would also reduce current. Temperature changes can alter resistance, but raising room temperature typically increases resistance for many common resistors, which would not help to increase current.