The magnetic field existing in a region is gicen by `vecB =B_0(1+(x)/(l))vec k.` A square loop of edge l and carrying a current I, is placed with its edges parallel to the x-y axes. Find the magnitude of the net magnetic force experienced by the loop.

Explanation

Wire `AB: x = 0, vec(B) = 0, F_(AB) = 0`
Wire `CD: x = L, vec(B) = B_(0) ((x)/(L) + (2x^(2))/(L^(2))) hat(k) = 3B_(0)hat(k)`
`F_(CD) = 3 B_(0) i L`, towards right
Force on `BC` is equal and opposite to force on `DA`
`(F_("net"))_("loop") = F_(CD) = 3B_(0)iL`, towards right