The amplitude of waves observed by two light sources of the same wavelength are $a$  and $2a$ and have a phase difference of $\pi$ between them. Then the minimum intensity of light will be proportional to:

The light waves from two independent monochromatic light sources are given by, $y_1=2\sin (\omega t-kx) \text{and} y_2=3\cos (\omega t-kx)\text{,}$ then the following statement is correct.

Two coherent monochromatic light beams of intensities $I$ and $4I$ are superposed. The maximum and minimum possible intensities in the resulting beam are