If resistors are connected in series,the current through each resistor remains the same.

Sonika is working with the circuit shown in the figure. There are two open terminals in the circuit: $X$ and $Y$. She has wires made of five different materials: $I, II, III, IV,$ and $V$. She knows that the electric bulb will glow only when wires made of conducting materials are connected across both open terminals. She records her observations in a table. After the experiment,ink spills on the paper,and she loses the information for the third row.

$S.No.$	Material at $X$	Material at $Y$	Electric Bulb ($ON$/$OFF$)
$1$	$I$	$II$	$OFF$
$2$	$I$	$IV$	$ON$
$3$	-	-	$OFF$
$4$	$III$	$V$	$ON$

Based on the remaining information in the table,which materials could be in the third row?

Mention two special features of the material to be used as an element of an electric iron.

The resistance of a conducting wire is $10\, \Omega$. If a battery of $1.5\, V$ is connected to it,then how much electric current will flow through it (in $, mA$)?

An electric iron consumes energy at a rate of $840\, W$ when heating is at the maximum rate and $360\, W$ when the heating is at the minimum. The voltage is $220\, V$. What are the current and the resistance in each case?

What is the $SI$ unit of electric charge?