I still don\'t get why the compass moved in both direction, what forces are acti
ID: 1402401 • Letter: I
Question
I still don't get why the compass moved in both direction, what forces are acting on the compass please explain in detail!
so we did our lab on AC fields and in the lab we adjusted the function generator to frequency of 2.5 Hz and we placed a compass next to opening of coil with 800 turns and we observed that when frequency was increased to 2.5 Hz and when the compas was placed near the coil, the compass needle started to rotate in both rotations very quickly but when it was moved further away the compas moved very slowly in both directions. So my question is that why did the compass rotate so quickly when it was moved closer to the coil? it involves some kind of magnetic force acting on the compass or something but I am confused what is acting on the compass and the coil?
The setup for this section is shown below:
Explanation / Answer
The compass needle is moving in both directions becuause of the change in the direction of magnetic field around the coil . The compass needle move in one direction when the current through the coil is flowing in one directon. When the direction of AC current changes to other direction, which cuauses to reverse the diretion of magnetic field. Therefore needle moves in opposited direction after fixed interval. SO, due to the change in the direction of alternating currentcthrough the coil the magnetic feild produced around the coil also reverses its direction. This is the reason why the needle of compass reverses its direction after equal interval of time.