Which equation expresses Ohm's law to solve for current?

Which equation expresses Ohm's law to solve for current?

• A. I = V / R
• B. V = IR
• C. R = V / I
• D. I = R / V

Answer: (A)

Ohm's law links current, voltage, and resistance. To solve for current, you use I = V / R. This means the amount of current depends on how strong the driving voltage is and how much the device resists that flow. If you know the voltage across a component and its resistance, divide the voltage by the resistance to get the current in amperes. For example, with a 9-volt source and a 3-ohm resistor, the current is 9 V ÷ 3 Ω = 3 A. The units check out since volt divided by ohm equals ampere. You can also rearrange the same relationship to V = IR or R = V / I, but when you need to find current directly, the form I = V / R is the one to use.

Ohm's law links current, voltage, and resistance. To solve for current, you use I = V / R. This means the amount of current depends on how strong the driving voltage is and how much the device resists that flow. If you know the voltage across a component and its resistance, divide the voltage by the resistance to get the current in amperes. For example, with a 9-volt source and a 3-ohm resistor, the current is 9 V ÷ 3 Ω = 3 A. The units check out since volt divided by ohm equals ampere. You can also rearrange the same relationship to V = IR or R = V / I, but when you need to find current directly, the form I = V / R is the one to use.