What formula is used to calculate current in a circuit?

The formula used to calculate current in a circuit is derived from Ohm's Law, which states that the current (I) through a conductor between two points is directly proportional to the voltage (E) across the two points and inversely proportional to the resistance (R). This relationship is expressed mathematically as I = E / R.

In this formula, current is measured in amperes (A), voltage in volts (V), and resistance in ohms (Ω). By using this equation, one can determine how much current will flow in a circuit when the voltage and resistance are known. For example, if you have a circuit with a voltage of 10 V and a resistance of 2 Ω, you would calculate the current as 10 V divided by 2 Ω, resulting in 5 A.

The other choices do not align with Ohm's Law, which is why they do not represent the correct formula for calculating current.