I have to determine the polarity of the Capacitor in the given diagram.
I Approached the problem as follows:
When Magnet 1 moves with its North pole towards the coil, emf is induced in the coil as the magnetic flux through the coil changes. So, when seeing from the left hand side (i.e. from magnet 1) the direction of induced current appears to be Anticlockwise. Though, on seeing from the left hand side, the South pole of magnet is coming towards, according to Lenz's Law the coil will behave like a South pole, thus the direction of current is Clockwise. I am stuck at this point. How shall I proceed?
My textbook explained it this way which I did not understand:
The direction of induced current when seen from the left hand side is Anticlockwise, and its direction is Clockwise when seen from right hand side.Thus, direction of induced current is in Clockwise sense (why?) . This implies Plate A is positive plate and point B is negative one.
Please Help.
Best Answer
The best way to think about this is imagine the capacitor plates A and B to be behind the paper plane and then think about the direction of current induced. Observe it from the right magnet's side whose South Pole is approaching so the face of coil facing that South Pole will itself produce clockwise current in the coil. So the current flows from high potential A to low potential B.