$A$ very high magnetic field is applied to a stationary charge. Then the charge experiences

An electron is moving with a speed of $10^8 \ m/s$ perpendicular to a uniform magnetic field of intensity $B$. Suddenly,the intensity of the magnetic field is reduced to $B/2$. The radius of the path becomes from the original value of $r$:

$A$ particle of mass $m$ and charge $q$,accelerated by a potential difference $V$,enters a region of a uniform transverse magnetic field $B$. If $d$ is the thickness of the region of $B$,the angle $\theta$ through which the particle deviates from the initial direction on leaving the region is given by

Consider the mass spectrometer as shown in the figure. The electric field between the plates is $E \ V/m$,and the magnetic field in both the velocity selector and in the deflection chamber has magnitude $B$. Find the radius $r$ for a singly charged ion of mass $m$ in the deflection chamber.

$A$ particle of mass $M$ and charge $Q$ moving with velocity $\vec{v}$ describes a circular path of radius $R$ when subjected to a uniform transverse magnetic field of induction $B$. The work done by the field when the particle completes one full circle is

An electron with kinetic energy $5 \ eV$ enters a region of uniform magnetic field of $3 \ \mu T$ perpendicular to its direction. An electric field $E$ is applied perpendicular to the direction of velocity and magnetic field. The value of $E$,so that the electron moves along the same path,is . . . . . $N C^{-1}$.
(Given: mass of electron $= 9 \times 10^{-31} \ kg$,electric charge $= 1.6 \times 10^{-19} \ C$)