The magnetic field existing in a region is given 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

` B =B_(0) (1 + (x)/(l) veck )`
Force on AB ,
` F_(1) = iB_(0)l (1 + (0)/(l))`
force on , CD
` F_(2)^(4) = iB _(0). 2l `
Net force
`F_(2) - F_(1) = iBL `
Because forces on BC and AD are cancelled.