children already know about electric current.
Sequence of events:
(a)Laptop, projector set up on trolley before lesson begins. Get
child to insert CD 'The Way Things Work (DK Multimedia). Click on
index. Type in Electric Bell. Press OK. View demonstration of how
electric bell works. Click on 'How it worked.' Click on words current,
contacts, electro-magnet, and spring.
you press the doorbell, you connect two electrical contacts and
electricity is switched on. Current flows around a circuit. A hammer
is attached to an electromagnet. As it goes towards the electromagnet,
it hits the bell.
the bar of the hammer hits the magnet, it breaks off the flow of
electricity to the electromagnet. The electromagnet loses its magnetism.
The hammer goes back to its original position. The cycle repeats
as long as the visitor presses the bell.
and Answers session. Take suggestions as to how workings of the
electric bell could be enacted or dramatised. Choose a group or
groups to do so at a later date.