With a resistance '$X$' connected in series with a galvanometer of resistance $100 \Omega$, it acts as a voltmeter of range $0 - 15 \text{ V}$. To double the range, a resistance of $1500 \Omega$ is to be connected in series with '$X$'. The value of '$X$' in $\Omega$ is

What is voltage sensitivity? Obtain its equation.

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

The current sensitivity of a moving coil galvanometer can be increased by

To convert a galvanometer into a voltmeter,one should connect a

Two moving coil galvanometers $A$ and $B$ having identical springs are placed in magnetic fields of $0.25 \ T$ and $0.5 \ T$ respectively. If the number of turns in $A$ and $B$ are respectively $36$ and $48$,and the areas of the coils $A$ and $B$ are $2.4 \times 10^{-3} \ m^2$ and $4.8 \times 10^{-3} \ m^2$ respectively,then the ratio of the current sensitivities of the galvanometers $A$ and $B$ is