$A$ leaf which contains only green pigments is illuminated by a laser light of wavelength $0.6328 \,\mu m$. It would appear to be

In the given figure,light of intensity $I$ is incident on a glass slab at point $A$ at an angle of incidence $\theta_1$. It undergoes partial reflection and partial refraction. At each reflection,$25\%$ of the incident energy is reflected. If interference occurs between the rays $AB$ and $A'B'$,then $I_{max}/I_{min} = \dots$ (in $: 1$)

The intensity of light from a continuously emitting laser source operating at $638 \,nm$ wavelength is modulated at $1 \,GHz$. The modulation is done by momentarily cutting the intensity off with a frequency of $1 \,GHz$. What is the farthest distance apart two detectors can be placed in the line of the laser light,so that they can see the portions of the same pulse simultaneously?
(Consider the speed of light in air $c = 3 \times 10^{8} \,m/s$)

The figure shows a schematic diagram of the arrangement of Young's Double Slit Experiment. Choose the correct statement$(s)$ related to the wavelength of light used.

Laser beams are used to measure long distances because

Light of different colours propagates through air: