$A$ fuse wire with radius $1\, mm$ blows at $1.5\, A$. The radius of the fuse wire of the same material to blow at $3\, A$ will be:

The Thomson coefficient of a conductor is $10 \mu V/K$. The two ends of the conductor are kept at $50^{\circ} C$ and $60^{\circ} C$,respectively. The amount of heat absorbed by the conductor when a charge of $10 C$ flows through it is:

$A$ cell sends a current through a resistance $R_1$ for time $t$. Now,the same cell sends a current through a resistance $R_2$ for the same time $t$. If the heat produced in both cases is the same,then the internal resistance of the cell is:

Assertion : An electric bulb becomes dim,when the electric heater in parallel circuit is switched on.
Reason : Dimness decreases after sometime.

$A$ battery consists of a variable number $n$ of identical cells,each having electromotive force $E$ and internal resistance $r$,connected in series. The terminals of the battery are short-circuited,and the current $I$ is measured. Which one of the graphs below shows the relationship between $I$ and $n$?

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?