Which expression gives voltage in terms of current and resistance?

• A. V = I / R
• B. V = R / I
• C. V = I - R
• D. V = I × R

Answer: (D)

Voltage is determined by Ohm’s law, which says voltage equals current times resistance. This means if more current flows through the same resistance, the voltage must rise, and if the resistance increases for the same current, the voltage also increases. The expression that captures this relationship is V = I × R. For example, 2 amperes through a 3-ohm resistor results in 6 volts. This aligns with units: amperes times ohms give volts. The other forms don’t work because they yield non-voltage units or mix quantities that don’t describe how voltage depends on current and resistance.