To demonstrate the process of thermoelectric production with a model.
Apparatus and materials: Pressure cooker, pipe, tennis ball, metal sheet, dynamo, bulb.
Procedure :
`rarr` Take a table-tennis ball and make three slits into it.
`rarr` Put semicircular fins cut out of a metal sheet into these slits.
`rarr` Pivot the tennis ball on an axle through its centre with a straight metal wire fixed to a rigid support. Ensure that the tennis ball rotates freely about the axle.
`rarr` Now connect a cycle dynamo to this.
`rarr` Connect a bulb in series.
`rarr` Direct a jet of water or steam produced in a pressure cooker at the fins. Note down your observation.

Observation : The bulb gets lighted.
How electricity generated in this simple model ?

Explanation

The heat given to pressure cooker produces steam. The steam is used to turn the tennis ball (the turbine). The tennis ball is further linked to a dynamo. Therefore, armature of a dynamo rotates and generates electricity.