Assertion: When a charging particle is fires in a magnetic field the radius of tis circular path is directely proportional to the kinetic energy of the particle.
Reason: the centripetal force on the test charge `q_(0)` is `q_(0)vB` where `v` is the velocity of a partical and `B` is the magnetic field

Options

A. If both the assertion and reason are true and reason is a true explantion of the assertion.
B. If both the assertion and reason are true but the reason is not true the correct explantion of the assertion.
C. If the assertion is true but reason false
D. If both the assertion and reason are false.

Answer

C

Explanation

If the path of the charged particle is circular then radius of circular path is directely proportional to the speed and mass of the particle as `r=(mv)/(q_(0)B)`
`:.` Centripetal force `=(mv^(2))/r=q_(0) vB`