What is the current sensitivity of a galvanometer?

In the above diagram, a particle of mass $\text{'}\mathrm{m}\text{'}$ and charge $\text{'}\mathrm{q}\text{'}$initially moving along - axis with velocity ${\mathrm{v}}_{\mathrm{x}}$ enters the region between the two charged plates The length of the plate system  is $\mathrm{L}$ and a uniform electric field between the plate is $\mathrm{E}$  Find the vertical deflection of the particle at the far edge of the plate?

What is the basic principle of moving coil galvanometer?. Derive an expression for the current flowing through the galvanometer in terms of the steady angular deflection of its coil. Define voltage sensitivity of the galvanometer. What is a convenient way to increase its sensitivity?

A current-carrying solenoid is shown below Show that the magnetic field intensity at a point $\mathrm{P}$ be,

$\mathrm{B}=\frac{{\mathrm{\mu }}_0}{4\mathrm{\pi }}.\frac{2\mathrm{m}}{{\mathrm{r}}^3}$, where the symbols have their usual meaning.

Two long straight parallel conductors carry steady current ${\mathrm{l}}_1\mathrm{and} {\mathrm{l}}_2$ separated by a distance $\text{'}\mathrm{d}\text{'}$ if the currents are flowing in the same direction show how the magnetic field set up in one produces an attractive force on the other. Obtain the expression for this force. Hence define one ampere

Name the beautiful natural phenomenon that occur in the sky of polar region of earth due to helicon motion of charged particles.

A beam of ions with velocity $2\times {10}^{5 }m{s}^{-1}$enters normally into a magnetic field of $0·04T$. If the specific charge $\left(i.e.\frac{q}{m}\right)$ of ion is $5\times {10}^{7}CK{g}^{-1}$, find the radius of circular path described.