Which law is used to calculate the magnitude of the electric force between two electric charges?

The following table provides the resistivity of three samples:

Sample	$A$	$B$	$C$
Resistivity	$1.6 \times 10^{-8} \Omega \cdot m$	$5.2 \times 10^{-8} \Omega \cdot m$	$100 \times 10^{-6} \Omega \cdot m$

Which of them is suitable for heating elements of electrical appliances and why?

$A$ current of $1\, A$ is drawn by a filament of an electric bulb. The number of electrons passing through a cross-section of the filament in $16$ seconds would be roughly:

Two students perform experiments on series and parallel combinations of two given resistors $R_{1}$ and $R_{2}$ and plot the following $V-I$ and $I-V$ graphs. Which of the graphs is (are) correctly labelled in terms of the words 'series' and 'parallel'? Justify your answer.

Two resistors are connected in series as shown in the diagram. $(i)$ What is the current through the $5 \, \Omega$ resistor? (ii) What is the current through $R$? (iii) What is the value of $R$? (iv) What is the value of $V$?

$(a)$ Name the effect of electric current which is utilised in the working of an electrical fuse.
$(b)$ How is a fuse connected in a domestic circuit?