Question

A positively charged particle is moving in uniform circular path due to magnetic force in uniform magnetic field.Which of the following changes could cause the radius of the circular path to decrease?

• A. Increase the mass of the particle
• B. Increase the speed of the particle
• C. Decrease the charge of the particle
• D. Decrease the strength of the magnetic field
• E. None of the above

Answer 1

The correct option is E None of the above

Let the charge and mass of the particle be $q$ and $m$ respectively moving in a circular path in the region of uniform magnetic field $B$

Using $Bqr=mv$ $⟹r=\frac{mv}{Bq}$

Thus either increasing the mass or speed of the particle or decreasing the charge of particle or strength of magnetic field results in the increase of the radius of circular orbit.

Hence option E is correct.