A velocity selector consists of electric field … and magnetic field … with …. The value of … required for an electron of energy … moving along the positive …-axis to pass undeflected is : (Given, mass of electron … )

Electromagnetic Waves

JEE Main 2022 · 26 Jul, Evening shift · Q6798

PhysicsMedium120×since 2002Q6798

A velocity selector consists of electric field

\vec{E}=E \,\hat{k}

and magnetic field

\vec{B}=B \,\hat{j}

with

B=12 \,m T

. The value of

E

required for an electron of energy

728 \,\mathrm{e} V

moving along the positive

x

-axis to pass undeflected is : (Given, mass of electron

=9.1 \times 10^{-31} \mathrm{~kg}

)