If an electron is going in the direction of magnetic field $\overrightarrow B $ with the velocity of $\overrightarrow {v\,} $ then the force on electron is

The magnetic force acting on a charged particle of charge $-2\, \mu  C$ in a magnetic field of $2\, T$ acting in $y$ direction, when the particle velocity is $(2i + 3 j) \times  10^6\,\, m/s$ is

A $10 \;eV$ electron is circulating in a plane at right angles to a uniform field at magnetic induction $10^{-4} \;W b / m^{2}(=1.0$ gauss), the orbital radius of electron is ........ $cm$

A $2\, MeV$ proton is moving perpendicular to a uniform magnetic field of $2.5\, tesla$. The force on the proton is

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

When a charged particle moving with velocity $\vec v$ is subjected to a magnetic field of induction $\vec B$, the force on it is non-zero. This implies that