What is the resistance of an ideal ammeter?

Current sensitivities of two galvanometers $G_1$ and $G_2$ of resistances $100 \ \Omega$ and $50 \ \Omega$ are $10^8 \ \text{div/A}$ and $0.5 \times 10^5 \ \text{div/A}$ respectively. The galvanometer in which the voltage sensitivity is more is

In a galvanometer,$5 \%$ of the total current in the circuit passes through it. If the resistance of the galvanometer is $G$,the shunt resistance $S$ connected to the galvanometer is

Which one of the following modifications may increase the sensitivity of a moving coil galvanometer?
$1^{st}$ Way: By using a spring of smaller torsion constant.
$2^{nd}$ Way: By using a smaller coil.
$3^{rd}$ Way: By using a stronger magnet.
$4^{th}$ Way: By using a coil having fewer number of turns.

$A$ galvanometer has a resistance of $25 \, \Omega$ and a maximum of $0.01 \, A$ current can be passed through it. In order to change it into an ammeter of range $10 \, A$, the shunt resistance required is

The coil of a galvanometer consists of $100$ turns and an effective area of $1 \, cm^2$. The restoring couple per unit radian is $10^{-8} \, N \cdot m/rad$. The magnetic field between the pole pieces is $5 \, T$. The current sensitivity of this galvanometer will be: