Sun 27 Apr, 2014 07:26 pm
I was doing an experiment using magnets. The 1st experiment is using 4 couples of magnets placed beside conductor and the conductor is moved by controllers. The conductor is connected with a mikrovoltmeter to measure induced voltage. The 2nd experiment is using 5 couples of magnet and given the same treatment. The result is induced voltage in 1st experiment is greater than the 2nd . How could this happen? Isn't increasing amount of magnets will increase magnetic field? Note: the distance between magnet in 1st and 2nd expertiment is different. I placed magnets in a total distance 100 cm (so bcs of different amount the distance between magnet is different. And I'm using circle magnet)
The induced voltage is proportional to THE RATE OF CHANGE of magnetic flux, NOT the field strength. In your experiment it will depend on how you physically move the conductor (cross the field lines) through the surrounding field whose "field line distribution" will differ according to the arrangement of magnets.
What you call "motional emf" is what I have described. "Motion" is defined relative to the field lines, not the magnets themselves.