Two light sources with amplitudes 5 units and 3 units respectively interfere with each other. Calculate the ratio of maximum and minimum intensities.

Explanation

Amplitudes, `a_(1) = 5, a_(2) 3`
Resultant amplitude, `A=sqrt(a_(1)^(2)+a_(2)^(2)+2a_(1)a_(2)cosphi)`
Resultant amplitude is maximum when,
`phi=0,cos0=1,A_(max)=sqrt(a_(1)^(2)+a_(2)^(2)+2a_(1)a_(2))`
`A_(min)=sqrt((a_(1)-a_(2))^(2))=sqrt((5-3)^(2))=sqrt((2)^(2))=2units`
`1 prop A^(2)`
`(I_(max))/(I_(min))=((A_(max))^(2))/((A_(min))^(2))`
Substituting `(I_(max))/(I_(min))=((8)^(2))/((2)^(2))=(64)/(4)=16(or)I_(max):I_(min)=16:1`