A wire carries steady current. It is first bent to form a circular plane coil of one turn. The same length is now bent to give a double loop of smaller radius. The magnetic field produced at the centre by the same current will be:
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
Imagine that the magnetic field produced by single turn of coil be X. Now this is inversly proportional to the square of the radius of the coil (Use biot savarts law).Now in the second case the radius is exactly halved so it is (1/2) times now. The resultant field will be (1/1/2)^2*X=4X