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

$A$ galvanometer has a resistance of $25 \, \Omega$ and a maximum of $0.01 \, A$ current can be passed through it. In order to change it into an ammeter of range $10 \, A$, the shunt resistance required is

$A$ galvanometer gives full scale deflection with $0.006 \ A$ current. By connecting it to a $4990 \ \Omega$ resistance,it can be converted into a voltmeter of range $0-30 \ V$. If connected to a $\frac{2n}{249} \ \Omega$ resistance,it becomes an ammeter of range $0-1.5 \ A$. The value of $n$ is:

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

$A$ galvanometer of resistance $20 \,\Omega$ is to be converted into an ammeter of range $1 \, A$. If a current of $1 \, mA$ produces full scale deflection,the shunt required for the purpose is ................ $\Omega $.

$A$ galvanometer having a resistance of $20\,\Omega$ and $30\,divisions$ on both sides has a figure of merit of $0.005\,A/division$. The resistance that should be connected in series so that it can be used as a voltmeter up to $15\,V$ is ........... $\Omega$.