Page 136 - Science Class 06
P. 136
1. What is current electricity?
2. Why does current flow only in a closed
circuit?
3. Draw the diagram of the circuit of a
torch and write how electric current
flows through it.
An Electric Circuit
CONDUCTOR
Electric current flows when its path forms a
A conductor is any piece of material that
closed loop. A complete set up in which the
easily allows heat or electricity to pass
electric current can flow along a closed loop
through it. Many different materials can be
is known as an electric circuit.
conductors but metals are the best condu-
One important things about the electric c ng materials that are available to us. A
circuit is that current flows only when a cell conductor allows electrons to flow freely
and other components are connected in an across its surface.
unbroken loop.
Examples of Conductors:
Let’s take an example of a torch and study
how it works: 1. Copper wire is o en used in electrical
wire to conduct electricity.
Circuit of a Torch
A torch is powered by one or more cells. 2. Metal pots and pans transfer heat from
There is also a circuit inside the torch the stove to the food inside them to
through which current is passed. A torch cook it.
also consists of a switch and a small bulb. 3. A circuit board in a computer has many
The switch of the torch allows current to small metal wires that conduct electri-
pass through the circuit when needed. city from one part to another.
When current passes through the circuit the
4. Mixing metals with semi-metals like
bulb glows.
silicon creates superconduc ng materials
Look at the following diagram to under-
which allow for the integrated processing
stand the construc on of a torch and its
devices that run our newest phones and
circuit. computers.
Reflector Plas c casing Plas c casing Outer casing 5. Silver and aluminum are also good
conductors of heat and electricity.
Bulb
Eleci c cells
Arrangement of Two Cells in a Torch Silver and Aluminum
136 Science-6
