$A$ 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 ....... $\Omega$.

$A$ moving coil galvanometer of resistance $100 \ \Omega$ shows full-scale deflection when a current of $100 \ \mu A$ passes through it. If it is intended to show full-scale deflection when a current of $1 \ mA$ passes through it,the value of shunt resistance in ohms to be connected to the galvanometer is:

$A$ galvanometer having a resistance $G$ and current $I_g$ flowing in it,produces full-scale deflection. If $S_1$ is the value of the shunt which converts it into an ammeter of range $0-I$ and $S_2$ is the value of the shunt for range $0-8I$,then the ratio $\frac{S_1}{S_2}$ will be:

Given below are two statements: One is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A:$ For measuring the potential difference across a resistance of $600\,\Omega$,the voltmeter with resistance $1000\,\Omega$ will be preferred over a voltmeter with resistance $4000\,\Omega$.
Reason $R:$ $A$ voltmeter with higher resistance will draw smaller current than a voltmeter with lower resistance.
In the light of the above statements,choose the most appropriate answer from the options given below.

$A$ moving coil galvanometer has a rectangular wire coil of enclosed area $0.001 \ m^2$ and $500$ turns. The coil operates in a radial magnetic field of $0.2 \ T$ and carries a current of $6 \pi \times 10^{-8} \ A$. If the torsional spring constant is $6 \times 10^{-7} \ N-m/rad$, then the angular deflection of the coil in radians is

$A$ galvanometer of resistance $100 \Omega$ gives full scale deflection for a current of $1 \text{ mA}$. It is converted into an ammeter of range $0 - 10 \text{ A}$. The shunt required is: (in $\text{ }\Omega$)