Which formula gives current?

• A. I = V / R
• B. V = I * R
• C. R = V / I
• D. P = V * I

Answer: (A)

Current is the flow of electric charge, and Ohm's law ties together current, voltage, and resistance. The way to get current directly is to divide the voltage by the resistance: I = V / R. This form shows exactly how much current flows when you know the voltage across a component and its opposition to current. The other expressions describe different quantities: voltage is V = I × R, resistance is R = V / I, and power is P = V × I. They either refer to other quantities or would require rearranging to solve for current, whereas I = V / R gives current outright.