A current I flowing through the loop as shown in figure. The magnetic field at centre O is :
7μ0I16R⊗
7μ0I16R⊙
5μ0I16R⊗
5μ0I16R⊙
The effective magnetic field at O
B=BPE+BRS=μ04π·32πIR+μ04π·π2.I2R
⇒B=μ0I4R32+14=716μ0IR
As per Fleming's Right Hand rule, direction of magnetic filed is perpendicular and in the plane of paper.