Question

In an experiment of verification of Ohm’s law following observations are obtained.

Potential difference V (in volt)	0.5	1.0	1.5	2.0	2.5
current I (in ampere)	0.2	0.4	0.6	0.8	1.0

Draw a V-I graph and use this graph to find:

1. the potential difference V when the current I is 0.5 A,
2. the current I when the potential difference V is 0.75 V,
3. the resistance in a circuit.

Answer 1

1. 1.25 V
2. 0.3 A
3. The graph is linear, so resistance can be found from any value of the given table. For instance:
   When V = 2.5 Volt
   Current is I = 1.0 amp
   According to ohm's law :
   R = `"V"/"I"`
   R = `2.5/1.0`
   R = 2.5 Ω