The resistance of an ammeter is $13\, \Omega$ and its scale is graduated for a current up to $100\, A$. After an additional shunt has been connected to this ammeter,it becomes possible to measure currents up to $750\, A$ by this meter. The value of the shunt resistance is:

$A$ moving coil galvanometer is converted into an ammeter, reading up to $0.04 \,A$ by connecting a shunt of resistance '$3r$' across it and then into an ammeter reading up to $0.8 \,A$, 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 (in $\,A$)?

In a moving coil galvanometer,to make the field radial,what is done?

In the circuit shown below,the ammeter and the voltmeter readings are $3 \text{ A}$ and $6 \text{ V}$ respectively. Then the value of the resistance $R$ is

$A$ galvanometer has resistance '$G$' and range '$V_g$'. How much resistance is required to read voltage up to '$V$' volt?

$A$ galvanometer coil has a resistance of $50 \Omega$ and the meter shows full scale deflection for a current of $5 \text{ mA}$. This galvanometer is converted into a voltmeter of range $0-20 \text{ V}$ by connecting: