Page 87 - Science Class 6 Times Publication

c. Photo-cell

A photo-cell converts light energy into
electrical energy. It is used in solar
calculator, solar car, solar traf c light
and other solar devices. When sun light
falls on the photo-cells, electricity is
produced. A large number of photo-cells
are used in solar panel.

d. Generator and dynamo

Generator and dynamo also
produce electricity. They convert
mechanical energy into electrical
energy. Generally, dynamo is
used in bicycle to produce small
amount of current. But generators
are used in factories to produce
large amount of current. Dynamo
and generator both contain a coil
and a magnet kept nearer to each
other. When magnet or coil comes
in motion, current is produced in

the coil. In hydroelectric power station, owing water rotates the
turbine connected to the generator. The generator in return converts
the kinetic energy into electrical energy.

Electric circuit
Activity 8.1

Take a dry cell, 2 pieces of wire and a bulb. Connect one end of one
wire to positive terminal of the cell and one end of the another wire
to negative terminal of the cell. Connect other ends of both wires to
the bulb. What do you observe?

You will observe the glowing of the bulb. Here the bulb glows due to

the ow of current from the cell to the bulb. Thus, electric circuit is
formed.

Times' Crucial Science and Environment 83 Book 6