Question

The no. of waves made by an electron during its revolution in $5^{th}$ orbit is :

• A. 4
• B. 3
• C. 5
• D. 10

Answer 1

The correct option is C 5

We know that

$mvr=\frac{nh}{2\pi }$

Here the revolution is in 5th orbit so we get-

$mvr=\frac{5h}{2\pi }$

or

$2\pi r=\frac{5h}{mv}$

or

$2\pi r=5\lambda$

Hence five times the wavelength of electron is equal to the circumference of 5th orbit. So the electron makes five waves around 5th orbit.