(d) zero
At path difference \(\frac{\lambda}{2}\), destructive interference will occur. So intensity will be Imin
Let I1 = I2 = I0
∴ Imax = I1 + I2 + \(2 \sqrt{I_{1} I_{2}}\) = I0 + Io + 2I0 = 4I0
and Imin = I1+ I2 \(2 \sqrt{I_{1} I_{2}}\) = I0 + Io – 2I0 = 0