Interference is observed with two identical coherent sources. The intensity of the waves at a point of constructive interference is $I$. What is the intensity when one source is removed?

Travelling waves of wavelength $32 \mathrm{cm}$ are created in a closed-open pipe $\mathrm{X}$ of length $40 \mathrm{cm}$ and an open-open pipe $\mathrm{Y}$ of length $50 \mathrm{cm}$. In which pipe or pipes will a standing wave be formed?

Partially polarised light is a combination of completely unpolarised light and light that is polarised. Partially polarised light is transmitted through a polariser. As the polariser is rotated by $360°$, the ratio of the maximum to the minimum transmitted intensity is $7$.

Determine the fraction of the beam's intensity that is due to the polarised light.

In a two-slit experiment, red light is incident on two parallel slits. The light is observed on a screen far from the slits. The graph shows how the intensity of the light on the screen varies with distance $\text{y}$ from M.

The distance to the screen is 3.2 m and the separation of the slits is 0.39 mm.Determine the wavelength of light(in$°\mathrm{A}$)?