Assume that light of wavelength $600\, nm$ is coming from a star. The limit of resolution of a telescope whose objective has a diameter of $2\, m$ is $......... \times 10^{-7}\, rad$.

The diameter of the objective of a telescope is $10 \, cm$. There are two objects at a distance of $1 \, km$ from it. What should be the minimum distance between these two objects so that their images are seen as separate by this telescope? The wavelength of light is $5000 \, \mathring{A}$.

The resolving power of a microscope depends upon:

In an optical instrument- microscope, the wavelengths of light used are $\lambda_1 = 6800 \text{ Å}$ and $\lambda_2 = 5100 \text{ Å}$. The ratio of the resolving power of the microscope corresponding to $\lambda_1$ to that for $\lambda_2$ is

$A$ person is observing a bacteria through a compound microscope. For better analysis and to improve the resolving power,he should:

The limit of resolution of an oil immersion objective microscope of numerical aperture $0.8$ for light of wavelength $0.6 \mu m$ is