$A$ galvanometer has a coil of resistance $100 \, \Omega$ and gives a full-scale deflection for $30 \, mA$ current. If it is to work as a voltmeter of $30 \, V$ range,the resistance required to be added will be..... $\Omega$

$A$ galvanometer,having a resistance of $50 \Omega$,gives a full scale deflection for a current of $0.05 \text{ A}$. The length in metre of a resistance wire of area of cross-section $2.97 \times 10^{-2} \text{ cm}^2$ that can be used to convert the galvanometer into an ammeter which can read a maximum of $5 \text{ A}$ current is: (Specific resistance of the wire $= 5 \times 10^{-7} \Omega\text{-m}$)

Mark out the correct options.

If an ammeter is to be used in place of a voltmeter,then we must connect with the ammeter a

$A$ shunt of resistance $1\ \Omega$ is connected across a galvanometer of $120\ \Omega$ resistance. $A$ current of $5.5\ A$ flows through the circuit,and the galvanometer shows full-scale deflection. What is the current that would cause full-scale deflection in the galvanometer in the absence of the shunt (in $A$)?

Consider the following two 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 $10^{-3} \, ^\circ C$.