Question

n electrons, each carrying a charge e- are flowing across a unit cross section of a metallic wire in a unit time from east to west .write an expression for electric current and also give its direction of flow give reasons for your answer

Answer 1

as by the formula ne = it so current = ne/t , current always travel from high to low potential

Answer 2

Expression for electric current and its direction:

The direction of the current is always opposite to the direction of the electrons.

From question, we know that the direction of the electron is from east to west. So, the direction of the current will be west to east.

Magnitude of the current is given by the formula:

$\bold{i = \frac{dq}{dt}}$

Where,

$\bold{dq = Charge = n \times e^{-}}$

$\bold{dt = Time}$

Now, the current passing through electric wire for one second is given as:

$\bold{i = \frac{n \times e^{-}}{1}}$

Therefore, the electric current is $\bold{n \times e^{-}}$ and its direction is from west to east.