Question
Mon October 24, 2011 By:

can you tell me about easy to make working models in physics for class 11?

Expert Reply
Tue October 25, 2011
The easiest would be an electro magnet.  for this you will need a battery, some insulated wire, a steel nail, and switch.  

from one pole of the battery run a wire to a switch (a blade switch works the best but any kind will work), then from the other pole of the switch run the wire (20cm or so) and then strip 5 to 7 cm of insulation off of the wire.  This area of exposed wire is wrapped around the shaft of the nail and then the rest of the length of wire is attached  to the other end of the battery to complete the circuit.  when the switch is "off" the nail is not magnatized but  when the switch is on, the wire wrappings create a magnetic field in the nail and it becomes an electro magnet capable of picking up some steel and iron items like paper clips, tacks and iron filings.  When the switch is t urned off, these will fall off.
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