What is the function of the spiral spring in the construction of a galvanometer?

Voltmeters $V_1$ and $V_2$ are connected in series across a $D.C.$ line. $V_1$ reads $80 \, V$ and has a resistance per volt of $200 \, \Omega/V$. $V_2$ has a total resistance of $32 \, k\Omega$. The line voltage is ............. (in $V$)

The resistance of a galvanometer is $50\, \Omega$ and the maximum current which can be passed through it is $0.002\, A$. What resistance must be connected to it in order to convert it into an ammeter of range $0 - 0.5\, A$?

The resistance of a galvanometer is $25\,\Omega$ and it requires $50\,\mu A$ for full-scale deflection. The value of the shunt resistance required to convert it into an ammeter of $5\,A$ range is:

$A$ galvanometer of resistance $100 \Omega$ when connected in series with $400 \Omega$ measures a voltage of up to $10 \ V$. The value of resistance required to convert the galvanometer into an ammeter to read up to $10 \ A$ is $x \times 10^{-2} \Omega$. The value of $x$ is:

In a moving coil galvanometer,a strong horse-shoe magnet with concave-shaped pole pieces is used to: