Topic : diffraction

A parallel beam of monochromatic light of wavelength 450 nm passes through a long slit of width 0.2 mm. What is angular divergence in which most of the light is diffracted?

An objective lens of a telescope has diameter 200 cm. The limit of resolution of telescope for wavelength 600 nm is nearly

Consider the following statements a. Resolving power of a telescope is inversely proportional to wavelength of light used b. Light of different colours travel with different speed in vacuum Choose the correct statement

Wavelengths of light used are $\lambda_1 = 4000 \text{ Å}$ and $\lambda_2 = 5000 \text{ Å}$ then ratio of resolving powers of instrument (corresponding to $\lambda_1$ and $\lambda_2$) is