Two very long, straight, parallel wires carry steady currents $I$ and $-I$ respectively. The distance etween the wires is $d$. At a certain instant of time, a point charge $q$ is at a point equidistant from the two wires, in the plane of the wires. Its instantaneous velocity $v$ is perpendicular to the plane of wires. The magnitude of the force due to the magnetic field acting on the charge at this instant is
$\frac{{{\mu _0}Iqv}}{{2\pi d}}$
$\frac{{2{\mu _0}Iqv}}{{\pi d}}$
$\frac{{{\mu _0}Iqv}}{{\pi d}}$
$0$
A particle of mass $M$ and charge $Q$ moving with velocity $\mathop v\limits^ \to $ 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
A positively charged particle moving due east enters a region of uniform magnetic field directed vertically upwards. The particle will
Give definition of magnetic field and give its unit.
Two electrons are moving along parallel lines unidirectionarly with same velocity they will
An electron with kinetic energy $5 \mathrm{eV}$ enters a region of uniform magnetic field of $3 \mu \mathrm{T}$ perpendicular to its direction. An electric field $\mathrm{E}$ is applied perpendicular to the direction of velocity and magnetic field. The value of $\mathrm{E}$, so that electron moves along the same path, is . . . . . $\mathrm{NC}^{-1}$.
(Given, mass of electron $=9 \times 10^{-31} \mathrm{~kg}$, electric charge $=1.6 \times 10^{-19} \mathrm{C}$ )