Q. An electron $(e = 1.6 \times 10^{- 19}C)$ moves in a circular orbit of radius 1.42 cm with a speed of $10^{5}\ ms^{- 1}$ in presence of magnetic field of $4 \times 10^{- 2}$T. If the mass of electron is $9.1 \times 10^{- 31}$ kg the energy gained by the electron in going one round the circular orbit is
A) zero
B) $4.54\ \times 10^{- 28}$ J
C) $9.08 \times 10^{- 28}$ J
D) $28.55\ \times 10^{- 28}$ J
Explanation
The correct answer is Option A: zero.
A detailed explanation for this question is being prepared.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.