clear
//
//
//

//Variable declaration
d=0.2*10**-3          //distance between slits(m)
lamda=550*10**-9      //wavelength(m)
D=1                   //distance of screen from slits(m)

//Calculation
beta1=lamda*D/d       //fringe width(m)

//Result
printf("\n fringe width is %0.3f  mm",beta1*10**3)