Question

An experiment is performed to verify Ohm's law. Observations are tabulated as follows:
$\begin{array}{cccccc}Current\left(I\right)inamperes& 0.1& 0.2& 0.3& 0.4& 0.5\\ Potentialdifference\left(V\right)involts& 1.2& 2.4& 3.6& 4.8& 6.0\end{array}$
(a) From the data, plot a V-I graph.
(b) Show that the graph confirms the Ohm's law.
(c) Find the resistance of the resistor used.
[5 MARKS]

Answer 1

part a: 2 Marks
part b: 1 Mark
part c: 2 Marks

(a) The required graph is shown in Fig. 8.24.

(b) We see that the graph drawn potential difference versus current is a straight line. This confirms the Ohm's law.
(c) The slope of the straight line on V-I graph gives the resistance of the resistor.
$\therefore$ Resistance $=\frac{\Delta V}{\Delta I}=\frac{7.2-0}{0.6-0}=\frac{7.2}{0.6}=12\Omega$