A parabolic section of wire OA is located in the x-y plane and carries current `I=12 A`. A uniform magnetic field `B=4.0 T` making an angle `60^(@)` with x axis exists in x-y plane. Calculate the magnetic force on the wire OA. Coordinates of A are (0.25 m, 1 m)

Options

A. `6(sqrt(3)-4)hat(k)N`
B. `6(4-sqrt(3))hat(k)N`
C. `3(sqrt(3)-4)hat(k)N`
D. `3(4-sqrt(3))hat(k)N`

Answer

A

Explanation

Magnetic fields is uniform, apply `vec(F)=Ivec(L)xxvec(B)` where
`vec(L)=0.25hat(i)+hat(j) and hat(B)=4(cos 60 hat(i)+sin 60hat(j))`