Chapter-4|Moving Charges and Magnetism| NCERT 12th Physics:
Circular Current Loop as a Magnetic Dipole:
Main Topic:
A current loop behaves as a magnetic dipole
Magnetic field lines are always from South(S) to North(N).
If we look at the upper face, current is showing clockwise, so it has South polarity. If we look at lower face current is anticlockwise, so it has north polarity.
That means current loop behaves as a system of two equal and opposite poles, hence it acts as a magnetic dipole.
Magnetic Dipole Moment:
Magnetic dipole moment M= IA
Note: In barmagnet direction is South to North. If n is the number of turns in the coil, then
Direction of Dipole Moment:
Curl your right hand fingers in the direction of current, the thumb now points in the direction of magnetic dipole moment or (area vector A).
Other Method to Find out North or South Pole in Current Circular Loops: