Four light sources produce the following four waves :(i) $y_1= a \sin(\omega t+\phi _1)$ (ii) $y_2= a \sin 2 \omega t $ (iii) $y_3= a' \sin(\omega t+\phi _2)$ (iv) $y_4= a' \sin(3 \omega t+\phi)$ Superposition of which two waves give rise to interference ? - Clay6.com, a Free resource for your JEE, AIPMT and Board Exam preparation

Four light sources produce the following four waves :(i) $y_1= a \sin(\omega t+\phi _1)$ (ii) $y_2= a \sin 2 \omega t $ (iii) $y_3= a' \sin(\omega t+\phi _2)$ (iv) $y_4= a' \sin(3 \omega t+\phi)$ Superposition of which two waves give rise to interference ?