An electron enters a region where magnetic $(B)$ and electric $(E)$ fields are mutually perpendicular to one another,then

The magnetic force depends on $v$,which depends on the inertial frame of reference. Does the magnetic force differ from one inertial frame to another? Is it reasonable that the net acceleration has a different value in different frames of reference?

Give the definition of magnetic field and provide its unit.

The electrostatic force $(\vec{F}_1)$ and magnetic force $(\vec{F}_2)$ acting on a charge $q$ moving with velocity $\vec{v}$ can be written as:

$A$ metal sample carrying a current along the $x-$ axis with current density $J$ is subjected to a magnetic field $B$ (along the $z-$ axis). The electric field $E$ developed along the $y-$ axis is directly proportional to $J$ as well as $B$. The constant of proportionality has the $SI$ unit:

An electric charge $+q$ moves with velocity $\overrightarrow{V} = 3\hat{i} + 4\hat{j} + \hat{k}$ in an electromagnetic field given by $\overrightarrow{E} = 3\hat{i} + \hat{j} + 2\hat{k}$ and $\overrightarrow{B} = \hat{i} + \hat{j} - 3\hat{k}$. The $y$-component of the force experienced by $+q$ is: (in $q$)