Q. An electron has a circular path of radius 0.01 m in a perpendicular magnetic induction $10^{- 3}$ T. The speed of the electron is nearly
A) 1.76 $\times 10^{4}\ ms^{- 1}$
B) 1.76 $\times 10^{6}\ ms^{- 1}$
C) 3.52 $\times 10^{6}\ ms^{- 1}$
D) 7.04 $\times 10^{6}\ ms^{- 1}$
Explanation
(b) $Bev = mv^{2}/r$ or $v = Ber/m$
$= \ \frac{10^{- 3} \times 1.6 \times 10^{- 19} \times 0.01}{9.0 \times 10^{- 31}}$
$= 1.77\ \times 10^{6}\ ms^{- 1}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.