Physics - Geometrical Optics Question with Solution | TestHub

Four light sources produce the following four waves: (i) $y_1=a\sin \left(\omega t+{\varphi }_1\right)$ (ii) $y_2=a\sin 2\omega t$ (iii) $y_3=a\sin \left(\omega t+{\varphi }_2\right)$ (iv) $y_4=a\sin (3\omega t+\varphi )$ Superposition of which two waves give rise to interference?