An electron is accelerated by a potential difference of 12000 volts. It then enters a uniform magnetic field of `10^(-3)T` applied perpendicular to the path of electron. Find the radius of path. Given mass of electron `=9xx10^(-31)kg` and charge on electron `=1.6xx10^(-19)C`

Options

A. 36.7 m
B. 36.7 cm
C. 3.67 m
D. 3.67 cm

Answer

B

Explanation

`r = (sqrt(2mK))/(qB) = (1)/( B) sqrt((2mV)/(q))`
`= (1)/(10^(-3)) sqrt((2 xx 9 xx 10^(-31) xx 12000)/(1.6 xx 10^(-19))) = 0.367 = 36.7` cm