Consider two identical galvanometers and two identical resistors with resistance $R$. If the internal resistance of the galvanometers is $R_G < R/2$,which of the following configurations yield the maximum voltage range and maximum current range?

$A$ galvanometer of resistance $50 \ \Omega$ is connected to a battery of $8 \ V$ along with a resistance of $3950 \ \Omega$ in series. $A$ full-scale deflection of $30$ divisions is obtained in the galvanometer. In order to reduce this deflection to $15$ divisions,the resistance in series should be . . . . . . $\Omega$.

We have a galvanometer of resistance $25\,\Omega$. It is shunted by a $2.5\,\Omega$ wire. The part of the total current that flows through the galvanometer is given as:

$A$ moving coil galvanometer is converted into an ammeter reading up to $0.03\,A$ by connecting a shunt of resistance $4r$ across it,and into an ammeter reading up to $0.06\,A$ when a shunt of resistance $r$ is connected across it. What is the maximum current which can be sent through this galvanometer if no shunt is used?

Give the unit of shunt.

The ratio of heats generated through shunt and galvanometer is $7: 5$ when they are connected to make an ammeter. If the resistance of the galvanometer is $112 \Omega$,then the resistance of the shunt is: (in $Omega$)