Q.

An electron revolves around an infinite cylindrical wire having uniform linear charge density 2×10-8 Cm-1 in a circular path under the influence of attractive electrostatic field as shown in the figure. The velocity of the electron with which it is revolving is __________ ×106 ms-1. Given, mass of electron =9×10-31kg.     [2023]


Ans.

(8)

eE=mv2r

e2kλr=mv2r

v=e·2kλm=1.6×10-19×2×9×109×2×10-89×10-31

=8×106 m/s