Question

If an electron revolves in the path of a circle of radius of $0.5\times {10}^{-10}m$ at a frequency of $5\times {10}^{15}$ cycles/sec then find the electric current in the circle.

Answer 1

Given: an electron revolving in the path of a circle of radius of $0.5\times {10}^{-10}m$ at a frequency of $5\times {10}^{15}$ cycles/sec

To find the electric current in the circle

Solution:

The formulas used

$\text{current}=\frac{\text{charge}}{\text{time}}$

and $\text{Time period}=\frac{1}{\text{frequency}}$

and $\text{distance}=2\pi r$

According to the question, $r=0.5\times {10}^{-10}m$, frequency = $5\times {10}^{15}$ cycles/sec

Therefore, $\text{current}=2\pi r\times \text{frequency}⟹\text{current}=2\times 3.14\times 0.5\times {10}^{-10}\times 5\times {10}^{15}⟹\text{current}=15.7\times {10}^{5}A$

is the required electric current in the circle.