Diamagnetic material
\({ \mu }_{ r }=1+{ x }_{ m }\)

Given current sensitivity
 \({ I }_{ S }=20\mu A{ div }^{ -1 }=20\times { 10 }^{ -6 }A{ div }^{ -1 }\) 
The galvanometer ha 30 divisions, so current for full-scale deflection
,\({ I }_{ g }=30\times 20\times { 10 }^{ -6 }A=6\times { 10 }^{ -4 }A\) 
When the galvanometer is to be converted into an ammeter, thus the value of shunt required
\(S=\frac { { I }_{ g } }{ I-{ I }_{ g } } G=\frac { 6\times { 10 }^{ -7 } }{ 1-6\times { 10 }^{ -4 } } \times 25\)  (in parallel)
\(\\ =0.015\Omega \)
When the galvanometer is to be converted into a voltmeter, then the value of resistance R is given by
\(R=\frac { V }{ I } -{ R }_{ A }\) 
\(=\frac { 1 }{ 1 } -\frac { GS }{ G+S } =1-\frac { 25\times 0.015 }{ 25+0.015 } \)
\(=1-0.015=0.985\Omega \) (in series)

(i) Given 
 \(d B=0.2T,\theta =30°,\tau =0.06Nm\) 
\( \tau =MB\sin { \theta }\)
\( \therefore d M=\frac { \tau }{ B\sin { \theta } } =\frac { 0.06 }{ 0.2\times \sin { 60° } } =0.06{ Am }^{ 2 }\)
(ii) Potential energy of magnetic dipole in a uniform magnetic field B is given by
\(U=-MB\cos { \theta } \) 
In stable equilibrium, the potential energy is minimum i.e.\(\cos { \theta } =1 \ or \ \theta =0°\)
So for stable equilibrium, the magnet must be aligned with its magnetic moment parallel to the magnetic field.