A square loop of side cm carries a current A. Calculate magnetic induction (in T) at point , lying on the axis of loop and at a distance cm from the centre loop |

A square loop of side cm carries a current A. Calculate magnetic induction (in T) at point , lying on the axis of loop and at a distance cm from the centre loop |

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Axis of the loop means a line passing through centre of loop and normal to its plane. Since distance of the point is from centre of loop and side of square loop is a as shown in figure (a)

Therefore, perpendicular distance of from each side of the loop is,

Now, consider only one side of the loop as shown in figure (b)

Magnitude of magnetic induction at , due to current in this side , is

Now, consider magnetic inductions, produced by currents in two opposite sides and as shown in figure

Components of these magnetic inductions, parallel to plane of loop neutralize each other. Hence, resultant of these two magnetic induction is (along the axis)

Similarly, resultant of magnetic inductions produced by currents in remaining two opposite sides and will also be equal to (along the axis in same direction). Hence, resultant magnetic induction