03.2 Electric Current 1. Electric current (I) is defined as the rate at which charge flows through a cross-sectional area. 2. For steady current, = q I t , where q is the net charge and t is the time interval. 3. Current can flow in both directions and if the current is negative, it indicates a flow in the opposite direction
4. For non-steady currents, the instantaneous current is defined as 0 lim → = t Q I t , where Q is the charge flowing in time t . 5. The SI unit of electric current is the ampere (A). 6. Currents in household devices are typically of the order of a few amperes, while lightning carries tens of thousands of amperes.
Ohm’s Law:
According to Ohm’s Law, the electric current flowing through any conductor is proportional to the voltage applied across its ends.
If I is the current flowing through the conductor, and V is the potential difference between two points, then according to Ohm’s law,
V ∝ I
Ohm’s Law is a fundamental concept that will be applied to many advanced levels later. Therefore, we encourage students to have a sound knowledge of each topic and avoid rote learning. . We recommend students to study from our Class 12 Physics Chapter 3 Notes where our Physics faculty experts have explained Ohm’s Law in greater detail.
