Question

In an experiment of verification of Ohm's law, following observations are obtained.
$$\begin{array}{cccccc}\text{Potential difference V (in Volt)}& 0.5& 1.0& 1.5& 2.0& 2.5\\ \text{Current I (in ampere)}& 0.2& 0.4& 0.6& 0.8& 1.0\end{array}$$
Draw a V- I graph and use this graph to find :
(a) the potential difference V when the current I is 0.5 A,
(b) the current I when the potential difference V is 0.75 V,
(c) the resistance in circuit.

Answer 1

(a) 1.25 V
(b) 0.3 A
(c) The graph is linear, so resistance can be found from any value of the given table.

For instance: When V = 2.5 volts
Current, I = 1.0 ampere
According to Ohm's law, $R=\frac{V}{I}=\frac{2.5}{1}=2.5\Omega$