A current carrying closed loop in the from of a right angle isoseles triangle `ABC` is placed in a unifrom magnetic fild acting along `AB`. If the magnetic force on the arm `BC` is `F`, the force on the arm `AC` is

Options

A. `sqrt2 vecF`
B. `-sqrt2 vecF`
C. `-vecF`
D. `vecF`

Answer

C

Explanation

Force on AB is zero
`F_(AB) = 0`
`implies F_(AB) + F_(BC) + F_(CA) = 0`
`implies F_(BC) + F_(CA) implies F_(CA) = - F_(BC) = - F`