(i) Draw a labelled circuit diagram to study a relationship between potential difference (V) across the two ends of a conductor and the current (I) flowing through it. State the formula to show how I in a conductor varies when V across it is increased step wise. Show this relationship also on a schematic graph.
Answer
The formula ie., Ohm’s law , states that the current passing through a conductor is directly proportional to the potential difference across its ends, provided the physical conditions like temperature, density etc. remain unchanged.
Graph showing relationship between V and I:
(ii) Calculate the resistance of a conductor if the current flowing through it is 0.25
Answer
Given,
- I = 0.25 A
- V = 1 V
According to Ohm’s law,
V = IR
Where,
- V is potential difference
- I is electric current
- R is resistance
Therefore, R = V / I
= 1 / 0.25
= 4 ohm