Question

describe an activity to show variation of resistance with cross section area of a conductor

Answer 1

In above circuit diagram,plug in the key and note the reading in ammeter reading.

Now replace the wire (1) with wire (2) which is thicker than wire (1) and note the ammeter reading.

It is noted that ammeter reading is increased when thicker wire is placed instead of wire (1).Thicker wire means larger area of cross section.

The resistance R is inversely proportional to area of cross section.When area of cross section increase the resistance decreases.