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

The value of shunt resistance,that allows only $10 \%$ of the main current to pass through a galvanometer of resistance $99 \Omega$,is (in $Omega$)

The ratio of heats generated through shunt and galvanometer is $7: 5$ when they are connected to make an ammeter. If the resistance of the galvanometer is $112 \Omega$,then the resistance of the shunt is: (in $Omega$)

The circular coil of a galvanometer has $50$ turns. The coil has a radius of $1 \ cm$. The coil is placed in a radial magnetic field of $0.010 \ T$. The torsion coefficient of the spring on which the coil hangs is $3 \times 10^{-7} \ N-m-rad^{-1}$. Determine the deflection of the galvanometer's pointer if the current through the coil is $1.0 \ mA$. (in $^{\circ}$)

$A$ galvanometer of $50 \, \Omega$ resistance has $25$ divisions. $A$ current of $4 \times 10^{-4} \, A$ gives a deflection of one division. To convert this galvanometer into a voltmeter having a range of $25 \, V$, it should be connected with a resistance of

Consider the two following statements $A$ and $B$,and identify the correct choice given in the answers: $(A)$ Duddell's thermo galvanometer is suitable to measure direct current only. $(B)$ Thermopile can measure temperature differences of the order of $10^{-3} {}^{\circ}C$.