Question $3(25$ Marks $)$

a$)$ Describe briefly the effect of heat on solid conductors and state the mathematical model governing this phenomena.

b$)$ Using this phenomena in $($a$)$ a student designed an instrument for measuring the amount of heat. Table Q$3$ tabulates the data obtained from the instrument functional tests. Plot the data and determine the formula that measures temperature using resistivity of the conductor.

Table Q$3$

$\backslash$table$[[$S$/$No$.,\backslash$table$[[$Temperature$],[(C)$