By ammeter,which of the following can be measured?

The circular coil of a galvanometer has $50$ turns. The coil has a radius of $1 \ cm$. The coil is placed in a radial magnetic field of $0.010 \ T$. The torsion coefficient of the spring on which the coil hangs is $3 \times 10^{-7} \ N-m-rad^{-1}$. Determine the deflection of the galvanometer's pointer if the current through the coil is $1.0 \ mA$. (in $^{\circ}$)

An ammeter gives full scale deflection when a current of $1.0 \ A$ is passed through it. To convert it into a $10 \ A$ range ammeter,the ratio of its resistance $(G)$ to the shunt resistance $(S)$ will be:

$A$ 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.

$A$ voltmeter with internal resistance of $x\text{ }\Omega$ can be used to measure up to $20\text{ V}$. In order to increase its measuring range to $30\text{ V}$,the required modification is to . . . . . . .

$A$ galvanometer of resistance $30 \Omega$ is connected to a battery of emf $2 \text{ V}$ with $1970 \Omega$ resistance in series. $A$ full-scale deflection of $20$ divisions is obtained in the galvanometer. To reduce the deflection to $10$ divisions,the total resistance in series required is: (in $Omega$)