Two coherent sources produce the maximum intensity of 100 units at a point. The sources are of equal intensity. What will be the intensity of the light at the same point, if the intensity of one of the sources is reduced by 36% by reducing its width?

Imax=I12+I22+2I1I2Both have same intensity,Imax=(I)2+(I)2 +2I2+2I2Imax=4I100=4II=25I1=25 units Intensity of one of the source is reduced by 36%,So, I2=25−25×36100I2=16 units Resultant intensity at a point is given by,I=I12+I22+2I1I2I=25)2+(16)2+225×16I=81 units