Page 132 - Science Class 07
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current of 5 amperes flow through the circuit setup is called an electromagnet. Now, we can
otherwise it would melt down. say that electromagnet is a setup which can
There are two types of fuse in the market create magne c effect in a controlled way.
names kit-kat fuse and cartridge fuse. An electromagnet is made by winding enamelled
Kit-Kat Fuse copper wire around a so -iron core (insulated).
When an electric current is passed through the
In a kit-kat fuse, the fuse wires can be easily
windings, the so iron behaves like a strong
replaced by taking out the electric fuse carrier
magnet. But when electric current is sw ched
from the socket as it is made up of porcelain. It
off it loses it magne c effect.
saves us from electric shocks.
Kit-Kat Fuse
Cartridge Fuse Winding Emamelled Copper Wire
In a cartridge fuse, the fuse wire is put inside a Uses of Electromagnets
glass tube and its two ends are joined with two Electromagnets are used in various electrical
metallic caps. The glass tube can be easily put equipments, appliance, machines, etc.
inside or taken out from its holder. The two
Uses in Home Appliances
metallic caps complete the circuit and electric
Most of the electric appliances are used in the
current flows through it.
home use electromagne sm as the basic
working principle. Some electromagnets are
used in the home including electric fan, electric
doorbell, induc on cooker, magne c locks, etc.
In an electric fan, the electromagne c induc on
Cartridge Fuse keeps the motor rota ng on and makes the
blade of the fan to rotate. Also in an electric
Magne c Effect of Electric Current doorbell when the bu on is pressed, due to the
A great scien st ‘Hans Chris an Oersted’ electromagne c forces the coil gets energized
no ced that a needle gets deflected when the and the bell sounds.
electric current is passed through a wire placed Uses in Medical Field
near it. It made him realise that electric current
The uses of electromagnets are also seen in the
has a magne c effect.
medical field. MRI scan which is short for
When a piece of iron is wounded by wire and Magne c Resonance Imaging is a device which
an electric current is passed through the wire, uses electromagnets. The device can scan all
it behaves like a magnet, but when the current the ny details in the human body with the
is switched off, it loses its magne sm. This help of electromagne sm.
132 Science-7
