Q.
A charged particle moving in a uniform magnetic field penetrates a layer of lead and thereby losses one half of its kinetic energy. The radius of curvature of its path becomes :
The radius of circular path is given by r=qBμυ
If EK be kinetic energy of particle then its momentum p=mυ=2mEK
So, the radius is given by r=qB2mEK
So, r∝EK
Therefore, when kinetic energy is halved the radius is reduced to 21 times its initial value.