Q. A proton and an electron both moving with the same velocity $v$ enter into a region of magnetic field directed perpendicular to the velocity of the particles. They will now move in circular orbits such that
A) Their time periods will be same
B) The time period for proton will be higher
C) The time period for electron will be higher
D) The orbital radii will be the same
Explanation
(b) $qvB = mr\omega^{2} = mr4\pi^{2}/T^{2}$ or $T \propto \ \sqrt{m}.$ As mass of proton is higher than that of electron so $T_{P} > T_{e}.$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.