Question

An electron having mass (9.1 x ${10}^{-31}$ kg) and charge (1.6 x ${10}^{-19}$C) moves in a circular path of radius 0.5 m with a velocity ${10}^6$ m/s in a magnetic fied. Strength of magnetic filed is

Answer 1

Given : $q=1.6\times {10}^{-19}C$ $m=9.1\times {10}^{-27}kg$ $v={10}^{6}m/s$ $r=0.5m$

Radius of circular path $r=\frac{mv}{qB}$

Or $0.5=\frac{9.1\times {10}^{-31}\times {10}^6}{1.6\times {10}^{-19}\times B}$

$⟹B=11.375\times {10}^{-6}T=11.375\mu T$