If an ammeter is to be used in place of a galvanometer,then we must connect:

$A$ galvanometer of resistance '$G$' is shunted by a resistance of '$S$' ohm. To keep the main current in the circuit unchanged,the resistance to be put in series with the galvanometer is:

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 $10^{-3} {}^{\circ}C$.

Explain the solution to the difficulties that arise when using a galvanometer directly as an ammeter.

$A$ voltmeter essentially consists of

Explain the use of a galvanometer as a voltmeter.