Electromagnet
Content:
Key learning:
Safety:
Activity
Procedure:
Electromagnet (level 7th to 10th)
Electromagnet is a simple activity that helps us to understand that:
a. a current carrying wire acts as a magnet by creating a magnetic field around it
b. such a magnet is called Electromagnet
Be careful while using cutters to scrap the ends of the copper wire.
MAKING
MAGNETS
Permanent
magnet
1
3
Big iron needle/ Nail
1.5 volt
Battery
Paper
clips
Insulated
copper wire
2
Scrape both ends
Wind insulated copper
wire on nail
www.life-lab.org
On connecting the two
ends to a battery the
nail/ needle becomes an
electromagnet and can
attract paper clips.
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Summary:
Current flows through the coil when connected to the terminals of a battery. This makes the coil act as a magnet.
The strength of such an electromagnet depends on:
a. number of windings in the coil
b. amount of current flowing through the coil
c. presence of a ‘core’ of ferromagnetic materials like Iron.
Think :
Why does a 'core' behave like a magnet when current flows through it?
Relate:
Electromagnets are widely used in electromagnetic cranes, motors, generators, and Maglev trains.
Generator
Electro
magnet
Stator
Rotor
Scrap iron
and steel
Magnet B
Turbine
Generator shaft
Turbine
Crane
Wicket
gate
Water flow
Coiled wire
Magnet A
Turbine blades
References:
www.life-lab.org
Definition of Electromagnet: http://en.wikipedia.org/wiki/electromagnet
Image of Electric crane: http://www.allaboutcircuits.com/worksheets/em1.html
Image of DC motor: http://www.pyroelectro.com/tutorials/dc_motor/dcmotor.html
Image of Generator: http://ga.water.usgs.gov/edu/hyhowworks.html
Design procedure of Electromagnet: http://www.arvindguptatoys.com/toys/makingmagnets.html
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