Question

Describe an activity to show the variation of resistance with area of cross section of a conductor.

Answer 1

if the cross section area of a wire is increased then its resistance will be decreases.
in a circuit  of   battery eliminator  with ammeter , wire with more diameter will be have lesser resistance .

Answer 2

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.