Antimony and bismuth are usually used in a thermocouple,because

$A$ silver and a copper voltameter are connected in parallel across a $6\,V$ battery of negligible resistance. In half an hour,$1\,g$ of copper and $2\,g$ of silver are deposited. The rate at which energy is supplied by the battery will approximately be ............... $W$ (Given $E.C.E.$ of copper $= 3.294 \times 10^{-4}\,g/C$ and $E.C.E.$ of silver $= 1.118 \times 10^{-3}\,g/C$).

In the circuit as shown in the figure, the:

First,a set of $n$ equal resistors of $10 \; \Omega$ each are connected in series to a battery of emf $20 \; V$ and internal resistance $10 \; \Omega$. $A$ current $I$ is observed to flow. Then,the $n$ resistors are connected in parallel to the same battery. It is observed that the current is increased $20$ times. The value of $n$ is .... .

$A$ power of $100 \ W$ is used at $125 \ V$ to produce chlorine by electrolysis. How many $mg$ of chlorine are produced per minute? (The electrochemical equivalent of chlorine is $0.367 \times 10^{-6} \ kg/C$)

Which of the following graphs represents the variation of power loss in the external load with external resistance $R$?