When an electric heater is switched on, the current flowing through it $(I)$ is plotted against time $(t)$. Taking into account the variation of resistance with temperature, which of the following best represents the resulting curve?

The bulb which glows with maximum intensity in the given circuit is

Consider the following two statements $A$ and $B$,and identify the correct choice out of the given answers:
$A$. Thermo $e.m.f.$ is minimum at the neutral temperature of a thermocouple.
$B$. When two junctions made of two different metallic wires are maintained at different temperatures,an electric current is generated in the circuit.

Which of the following statements is true regarding the thermo $e.m.f.$ of a thermocouple?

Two current elements $P$ and $Q$ have current-voltage characteristics as shown below:
Which of the graphs given below represents the current-voltage characteristics when $P$ and $Q$ are in series?

$A$ 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 $= 1.118 \times 10^{-3}\,g/C$).