Strength of current is a measure of the amount or quantity of electric charge passing through a particular cross-sectional area of a conductor per unit time. It is generally expressed in amperes (A), named after the French scientist André-Marie Ampère.

Strength of current is directly related to the number of charge carriers (usually electrons) flowing through the conductor. The more charge carriers there are, and the faster they are moving, the stronger the current. It depends on two main factors:

1. Potential Difference: The potential difference, also known as voltage (measured in volts, V), is the driving force behind the flow of electric current. A higher potential difference across the conductor results in a stronger current.

2. Resistance: The resistance of the conductor (measured in ohms, Ω) opposes the flow of electric current. The higher the resistance, the weaker the current for a given potential difference.

The relationship between strength of current (I), potential difference (V), and resistance (R) is mathematically represented by Ohm's law:

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I = V / R

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According to Ohm's law, the strength of current flowing through a conductor is directly proportional to the potential difference across it and inversely proportional to its resistance.

In summary, strength of current refers to the rate at which electric charge moves through a conductor and depends on the potential difference and resistance in the circuit. It is a fundamental quantity in electrical circuits, used to analyze and calculate various electrical phenomena and circuit behaviors.