Current Electricity - Introduction | Physics4students

Описание: The branch of Physics which deals with the study of motion of electric charges is called current electricity. The external energy necessary to drive the free electrons in a definite direction is called electromotive force (emf). The emf is not a force, but it is the work done in moving a unit charge from one end to the other. The flow of free electrons in a conductor constitutes electric current.

Electric current: The current is defined as the rate of flow of charges across any cross sectional area of a conductor. If a net charge q passes through any cross section of a conductor in time t, then the current I is equal to q by t, where q is in coulomb and t is in second.