An ammeter has a range of $1 \, A$ without a shunt. The range can be varied by using different shunt resistances. The graph between shunt resistance $(S)$ and range $(I)$ will have the nature of which curve shown in the figure?

What is the function of the spiral spring in the construction of a galvanometer?

In order to pass $10\,\%$ of the main current through a moving coil galvanometer of $99\,\Omega$,the resistance of the required shunt is ............ $\Omega$.

$A$ galvanometer of resistance $G$ is shunted by a resistance $S$. To keep the main current in the circuit unchanged,what value of resistance should be connected in series with the galvanometer?

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:

$A$ galvanometer,whose resistance is $50\, \Omega$,has $25$ divisions. When a current of $4 \times 10^{-4}\, A$ passes through it,its needle deflects by one division. To use this galvanometer as a voltmeter of range $2.5\, V$,it should be connected to a resistance of ....... $\Omega$.