$A$ galvanometer of $25 \,\Omega$ resistance can read a maximum current of $6 \,mA$. It can be used as a voltmeter to measure a maximum of $6 \,V$ by connecting a resistance to the galvanometer. Identify the correct choice in the given answers.

Given below are two statements:
Statement $I$: If the number of turns in the coil of a moving coil galvanometer is doubled,then the current sensitivity becomes double.
Statement $II$: Increasing the current sensitivity of a moving coil galvanometer by only increasing the number of turns in the coil will also increase its voltage sensitivity in the same ratio.
In the light of the above statements,choose the correct answer from the options given below:

$A$ milliammeter of range $10 \, mA$ has a coil of resistance $1 \, \Omega$. To use it as a voltmeter of range $10 \, V$,the resistance that must be connected in series with it will be ............. $\Omega$.

$A$ moving coil galvanometer of resistance $100 \Omega$ is used as an ammeter using a shunt resistance $0.1 \Omega$. The maximum deflection current in the galvanometer is $100 \mu A$. Find the total current in the circuit so that the ammeter shows maximum deflection. (in $mA$)

$A$ galvanometer having a resistance of $9 \, \Omega$ is shunted by a wire of resistance $2 \, \Omega$. If the total current is $1 \, A$, the part of it passing through the shunt will be ............ $A$.

$A$ galvanometer has resistance $G \ \Omega$ and $I_g$ is the current flowing through it which produces full-scale deflection. $S_1$ is the value of the shunt which converts it into an ammeter of range $0$ to $3I$,and $S_2$ is the shunt value which converts it into an ammeter of range $0$ to $4I$. The ratio $S_2:S_1$ is: