MAGNETIC EFFECT OF ELECTRIC CURRENT
MAGNETIC EFFECT OF ELECTRIC CURRENT
Activity:
Magnetic compass works on the magnetic effect of electric current
A magnetic compass has a magnetic needle supported on a pivot
Magnetic needle always shows North - South direction when it is left undisturbed
When a magnet is placed near the electric wire
When electric current passes through the wire the magnetic needle diflects
When switching off the current the magnetic needle comes to lie in its North - South direction
This concludes that electric current produces the magnetic field and this is called electro magnetic effect
Aim : to observe magnetic effect in current carrying conductor
Apparatus required:
1) electric cell
2) a bulb
3) switch
4) insulated wires
5) magnetic needle
Procedure:
1) Connect the circuit as shown in figure
2) place a magnetic needle under the wire in North - South direction
4) positive terminal of electric cell should be in south ward
3) switch on the circuit
4) in the circuit the current will flow from south to north pole of the needle.
5) the needle deflects towards west according to SNOW rule
6) switch off the circuit
7) now change the direction of the electric cell in the circuit
8) positive terminal of electric cell should be in North ward
9) switch on the circuit
10) in the circuit the current will flow from north to south pole of the needle.
11) the needle deflects towards East
Conclusion:-
1) current carrying conductor behaves as a magnet
2) when electric current switched off wire loses its magnetism
3) magnetic poles of current carrying conductor changes with the direction of flow of current
Activity:
Aim: Making an electro magnet
Apparatus:
1) soft iron nail
2) flexible wire
3) electric cell
4) switch
5) iron paper pins
Procedure:
Connect the circuit as shown
Place some iron paper pins at one end of the iron nail
Switch on the supply
The pins are attracted to the nails
Switch off the current.
The paper pins will come down.
Conclusion:
The soft iron nail is magnetised when electric current passed through it. We can call nail as electro magnet
Strong electro magnets made using core made up of aluminium+nickel alloy called NICO
Activity:
Apparatus:
1) big wire
2) iron nail
3) some iron pins, blades, small nails
4) electric cells
Procedure:
Wound the copper wire around fifty turns on iron nail
Connect the two ends of wire wounded nail to battery through switch
Bring the small nails, pins , blades near to wire wounded nail there will be no effect
Switch on the supply
Wire wounded nail attracts all small nails, blades, and pins
The wire wound nail acquired magnetic power
Switch off the supply
Wire wounded nail losses magnetic power and all attracted iron pieces fall down
Conclusion:
Electrical energy converted to magnetic eney
This phenomenon applied in
Electro magnets
Electric motors
Electric bells
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