An ammeter with a resistance of $2 \,\Omega$ can measure up to $100 \,mA$. What resistance (in $\Omega$) must be connected in series to make it measure up to $5 \,V$?

What is voltage sensitivity? Write the equation for voltage sensitivity.

Explain the difficulties encountered when using a galvanometer directly as an ammeter.

The deflection in a moving coil galvanometer falls from $25$ divisions to $5$ divisions when a shunt of $24\ \Omega$ is applied. The resistance of the galvanometer coil will be: (in $\Omega$)

Moving coil galvanometers $M_{1}$ and $M_{2}$ have resistance,number of turns,area of coil,and magnetic field as follows:
$R_{1}=10 \Omega, R_{2}=14 \Omega, N_{1}=30, N_{2}=42$
$A_{1}=3.6 \times 10^{-3} \ m^{2}, A_{2}=1.8 \times 10^{-2} \ m^{2}, B_{1}=0.25 \ T, B_{2}=0.50 \ T$
(Spring constants are same for both galvanometers).
The ratio of $(i)$ current sensitivity and (ii) voltage sensitivity for galvanometer ($M_{2}$ to $M_{1}$) is respectively:

Write the equation for the series resistance required to increase the voltage range of a galvanometer by a factor of $n$.