ഹീറ്റ് ഡിറ്റക്ടര്‍

ഹീറ്റ് ഡിറ്റക്ടര്‍

PROJECT TITLE:

Heat Detector

Aim:

To make a heat detector.

Materials Required:

1. Wooden box 2. Cardboard piece 3. Rubber band 4. Pin

Procedure:

Stretch a rubber band around the sides of a wooden box. Then cut out a arrow from the piece of cardboard and, mount it on a pin, and push the pin under the rubber band. If you now bring a burning match or candle close to the rubber band, the cardboard arrow will rotate anti-clockwise. Move the flame near the other end and the arrow rotates clockwise. The heat causes a portion of the band to contract, rotating the pin and arrow. This is because rubber contracts when heated and expands when cooled.