According to Ohm's Law, which two quantities are directly proportional?

According to Ohm's Law, which two quantities are directly proportional?

• A. Current and resistance
• B. Voltage and power
• C. Voltage and current
• D. Voltage and resistance

Answer: (C)

The main idea here is how Ohm’s Law links voltage and current when resistance is fixed. Ohm’s Law says V = I R, so for a constant resistance, I = V / R. This means if you raise the voltage, the current rises in direct proportion (doubling the voltage doubles the current). So voltage and current are directly proportional. The other pairs don’t have that same straight-line relationship under typical fixed conditions. With a fixed voltage, increasing resistance lowers the current, so current and resistance are inversely related (not directly proportional). Voltage and resistance don’t have a simple direct proportionality either, because changing one while the other can change the current in a way that isn’t a single constant ratio between V and R.

The main idea here is how Ohm’s Law links voltage and current when resistance is fixed. Ohm’s Law says V = I R, so for a constant resistance, I = V / R. This means if you raise the voltage, the current rises in direct proportion (doubling the voltage doubles the current). So voltage and current are directly proportional.

The other pairs don’t have that same straight-line relationship under typical fixed conditions. With a fixed voltage, increasing resistance lowers the current, so current and resistance are inversely related (not directly proportional). Voltage and resistance don’t have a simple direct proportionality either, because changing one while the other can change the current in a way that isn’t a single constant ratio between V and R.