An electron having mass `9.1xx10^(-31)`kg, charge `1.6xx10^(-19)C` and moving with the velocity of `10^(6)m//s` enters a region where magnetic field exists. If it describes a circle of radius 0.2 m then the intensity of magnetic field must be _______ `xx10^(-5)T`.

Options

A. 14.4
B. 5.65
C. 2.84
D. 1.13

Answer

C

Explanation

`(mv^(2))/r=Bqv`
`thereforeB=(mv)/(qr)=(9.1xx10^(-31)xx10^(6))/(1.6xx10^(-19)xx0.2)`
`thereforeB=2.84xx10^(-5)T`