Question

A proton enters a perpendicular magnetic field of intensity ‘B’ with speed ‘v’. The proton moves along a circular path of radius ‘R’. If a deuteron enter in to the same magnetic field with same speed, the radius of its circular trajectory will be?​

Answer 1

Given:

Proton enters magnetic field and has radius R.

To find:

What will be the radius if deuteron enters the same field ?

Calculation:

General Expression of radius of moving charges is:

$r = \dfrac{mv}{qB}$

• For the proton , whose mass is M , will have a radius of :

$R= \dfrac{Mv}{qB}$

• Now, deuteron is an isotope of Hydrogen with 1 neutron and 1 proton. The neutron can be neglected as it is neutral.

• So, total protons will still be 1.

Hence, deuteron will also have the same radius.