An infinite current carrying wire passes through point O and is perpendicular to the plane containing a current carrying loop ABCD as shown in figure. Choose the correct option(s).

Options

A. (i), (ii)
B. (i), (iii)
C. (ii), (iii)
D. (ii), (iv)

Answer

B

Explanation

Force on `AB` and `CD = 0`, hence magnetic field due to long wire will be parallel/anti parallel to length.
Force on `BC: F_(BC) = int Bi dx = (mu_(0) Ii)/(2pi) int_(a)^(a + b) (d x)/(x)`
Force on `DA: F_(DA) = (mu_(0) Ii)/(2pi) 1n (1 + b//a)` in upward directed
`F_("net") = 0`
Magnetic moment is along `-z` direction and magnetic field is in `x-y` plane, `vec(M)` tries to align field so loop rotates clockwise.