Q.

The current of 5A flows in a square loop of sides 1m is placed in air. The magnetic field at the centre of the loop is X2×10-7T. The value of X is ______.            [2024]


Ans.

(40)

i = 5A,

Square of side = 1m

Magnetic field at centre will be into the plane (X), due to all four wires

Bnet=4B1

B1=Magnetic field due to one side,

B1=μ0.i4πr(sinθ1+sinθ2),  Here θ1=θ2=45°

r=12 m

B1=μ0.(5)4π(1/2)(12+12)

Bnet=4B1=402×10-2 tesla

 x=40