A square wire of each side l carries a current I . The magnetic field at the mid-point of the square

Step-by-step solution

B=4 [ ₀ 4 I a ( ₁+ ₂ ) ] Here, a= l 2 and ₁= ₂=45^ aligned B & =4 ₀ 4 I (l / 2) [ 1 2 + 1 2 ] & B= 16 2 [ ₀ 4 I l ]=8 2 ( ₀ 4 I l ) aligned