Question

20 million electron reaches X to a point Y in 2 micro second. what is direction and magnitude of current?
​

Answer 1

Given - Number of electrons - 20 million

Time - 2 micro second

Find - direction and magnitude of current

Solution - Magnitude of current is calculated by the formula -

Q = I*T.

In the formula, q is charge, I is current and t is time.

Further Q can be represented as -

Q = ne, where n is number of electrons and e is charge on electron.

Equating both the equations,

n*e = I*t

Keeping the values in equation-

n = 20 million = 2*10^7

T = 2 micro second = 2*10^-6 seconds.

2*10^7*1.6*10^-19 = I*2*10^-6

I = 1.6*10^-6 C

Direction of current will be from Y to X. This is because current is directed towards movement of positive charges.