What equation can be used to measure the current in a circuit?

What equation can be used to measure the current in a circuit?

• A. Q = It
• B. E = mc^2
• C. P = IV
• D. I = V/R

Answer: (D)

Understanding how current can be found in a circuit hinges on Ohm’s law, which links current, voltage, and resistance. Current is the flow of electric charges, and Ohm’s law tells us that the current through a conductor equals the voltage across it divided by its resistance: I = V/R. So if you know the voltage across a component and its resistance, you can directly calculate the current flowing through it. The other equations describe different quantities. Q = It relates total charge to current and time, so it’s about how much charge passes over an interval rather than the instantaneous current itself. E = mc^2 concerns energy and mass, not current. P = IV defines power and can be rearranged to I = P/V, but that isn’t the direct way to measure current in a simple circuit; Ohm’s law, I = V/R, is the standard relation for calculating current from voltage and resistance.

Understanding how current can be found in a circuit hinges on Ohm’s law, which links current, voltage, and resistance. Current is the flow of electric charges, and Ohm’s law tells us that the current through a conductor equals the voltage across it divided by its resistance: I = V/R. So if you know the voltage across a component and its resistance, you can directly calculate the current flowing through it.

The other equations describe different quantities. Q = It relates total charge to current and time, so it’s about how much charge passes over an interval rather than the instantaneous current itself. E = mc^2 concerns energy and mass, not current. P = IV defines power and can be rearranged to I = P/V, but that isn’t the direct way to measure current in a simple circuit; Ohm’s law, I = V/R, is the standard relation for calculating current from voltage and resistance.