In YDSE suppose two slits are illuminated by two different lights having wavelength ${\mathrm{\lambda }}_1 \mathrm{and} {\mathrm{\lambda }}_{2.}$Then 

Since wavelength of light emerging from the slits are different, their frequencies are different. Therefore the sources behave like incoherrent sources, Hence no definite fringe pattern is obtained on the screen and at any point intensity of light at any point on the screen is $({\mathrm{I}}_1+{\mathrm{I}}_2)$.
Select the correct option.