
Force on segment 1-2 and 3-4 will get cancel out.
Force on segment 4-1,
F1=2πaμ0I1I2×a toward Right
Force on segment 2-3:
F2=2π(2a)μ0I1I2×a toward left
Net force on loop:
Fnet=F1−F2 toward Right
=2πμ0I1I2−4πμ0I1I2
=4πμ0I1I2 toward Right or repulsive