Magnetic field due to current through a circular loop


Asked by meetmaheshwari08022004 | 31st Jan, 2021, 01:32: PM

Expert Answer:

It is known that current passing through wire produces magnetic field and direction of magnetic field depends
upon the direction of current as realized from right-hand rule. Suppose we consider that this straight wire is bent
in the form of a circular loop and a current is passed through it.  When current is passing through a wire magnetic
field lines form circumference of a circle. It is known that the magnetic field produced by a current-carrying straight
wire depends inversely on the distance from it.  In the case of wire bent in the form of circular loop,  at every point of a
current-carrying circular loop, the concentric circles representing the magnetic field around it would become larger and
larger as we move away from the wire as shown in the right side figure. By the time we reach at the centre of the circular
loop, radius of curvature of circular magnetic field lines keep on increasing. Hence at centre of loop, the arcs of these
big circles would appear as straight lines. Every point on the wire carrying current would give rise to the magnetic field
appearing as straight lines at the center of the loop. By applying the right hand rule, it is easy to check that every section
of the wire contributes to the magnetic field lines in the same direction within the loop.
Magnitude of magnetic field B at centre of circular loop is given as
B = ( μo I ) / ( 2 R ) 
where μo is the permeability of magnetic field , I is current and R is radius of loop 

Answered by Thiyagarajan K | 1st Feb, 2021, 01:37: AM

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