A circular loop of radius 4.0 cm is placed in a horizontal plane and carries an electric current of 5.0 A in the clockwise direction as seen from above. Find the magnetic field.

(a) at a point 3.0 cm above the center of the loop


(b) at a point 3.0 cm below the center of the loop.


Given:


Radius of circular loop(r) = 4 cm = 0.04 m


Current carried by it(i) = 5 A



Formula used:


Magnetic field at a distance x from the center of a current carrying circular loop(B),



Where


μ0 = magnetic permeability of vacuum = 4π x 10-7 T m A-1,


i = current carried by coil,


r = radius of coil


(a) To find the magnetic field 3 cm above the loop:


Magnetic field,



Here, x = 3 cm = 0.03 m


Hence, substituting the given values:



= 4.019 x 10-5 T (in the downward direction, by right hand thumb rule) (Ans)


(b) To find the magnetic field 3 cm below the loop:


Here, all the values are same as the previous part. Hence,


B = 4.019 x 10-5 T (in the upward direction, by right hand thumb rule)


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