In case Hall effect for a strip having charge $Q$ and area of cross-section $A$, the Lorentz force is

A uniform magnetic field $B$ and a uniform electric field $E$ act in a common region. An electron is entering this region of space. The correct arrangement for it to escape undeviated is

An electron moves with speed $2 \times {10^5}\,m/s$ along the positive $x$-direction in the presence of a magnetic induction $B = \hat i + 4\hat j - 3\hat k$ (in $Tesla$) The magnitude of the force experienced by the electron in Newton's is (charge on the electron =$1.6 \times {10^{ - 19}}C)$

A charge having $q/m$ equal to $10^8\, C/kg$ and with velocity $3 \times 10^5\, m/s$ enters into a uniform magnetic field $0.3\, tesla$ at an angle $30^o$ with direction of field. The radius of curvature will be ......$cm$

Mixed $H{e^ + }$ and ${O^{2 + }}$ ions (mass of $H{e^ + } = 4\,\,amu$ and that of ${O^{2 + }} = 16\,\,amu)$ beam passes a region of constant perpendicular magnetic field. If kinetic energy of all the ions is same then

A charged particle is moving with velocity $v$ in a magnetic field of induction $B$. The force on the particle will be maximum when