Question

An electron moves around the nucleus in a circular orbit of radius r and makes n revolutions per second. The value of equivalent current in the orbit is ______.

विकल्प

• `e/n`

• ne

• `(n e)/r`

• `e/(n r)`

Answer 1

An electron moves around the nucleus in a circular orbit of radius r and makes n revolutions per second. The value of equivalent current in the orbit is ne.

Explanation:

When a charged particle moves in a circular orbit, it constitutes an electric current. The current is defined as the rate of flow of charge.

Current I is given by:

I = `q/T`

Where:

q = Charge passing through a point

T = Time taken for one complete revolution

e = Charge of electron

n revolutions per second = Frequency of revolution

Time period T = `1/n` seconds

In each revolution, the electron passes any point on the circle once, carrying charge e.

Current (I) = `"Charge per revolution"/"Time per revolution"`

= `e/T`

= `e/(1//n)`

= e × n

= ne

∴ The equivalent current is ne, which depends only on the charge and frequency, not on the radius r