An electron beam passes through a magnetic field of $2 \times 10^{-3}\,Wb/m^2$ and an electric field of $1.0 \times 10^4\,V/m$ both acting simultaneously. The path of electron remains undeviated. The speed of electron if the electric field is removed, and the radius of electron path will be respectively
$10\times 10^6\,m/s,$ $2.43\,cm$
$2.5\times 10^6\,m/s,$ $0.43\,cm$
$5\times 10^6\,m/s,$ $1.43\,cm$
none of these
A beam of electrons is moving with constant velocity in a region having electric and magnetic fields of strength $20\;V{m^{ - 1}}$ and $0.5 T$ at right angles to the direction of motion of the electrons. What is the velocity of the electrons............ $m{s^{ - 1}}$
The motion of a charged particle can be used to distinguish between a magnetic field and electric field in a certain region by firing the charge
An electron moving towards the east enters a magnetic field directed towards the north. The force on the electron will be directed
As shown in the figure, the uniform magnetic field between the two identical plates is $B$. There is a hole in plate. If through this hole a particle of charge $q$, mass $m$ and energy $E$ enters this magnetic field, then the particle will not collide with the upper plate provided
When a proton is released from rest in a room, it starts with an initial acceleration $a_0$ towards west. When it is projected towards north with a speed $v_0$ it moves with an initial acceleration $3a_0$ toward west. The electric and magnetic fields in the room are