Q. Four charged particles are projected perpendicularly into the magnetic field with equal. Which will have minimum frequency?
A) Proton
B) Electron
C) ${Li}^{+}$
D) $He^{+}$
Explanation
(c) Frequency $f = \frac{Bq}{2\pi m}$
As proton, electron, $Li^{+},\ {He}^{+}$ have same charge in magnitude and since magnetic field is also constant.
So, $f \propto \frac{1}{m}$
Among the given charged particles, ${Li}^{+}$ has highest mass, therefore it will have minimum frequency.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.