The ratio of resolving powers of an optical microscope for two wavelength $$\lambda $$₁ = 4000 $$\mathop A\limits^ \circ $$ and $${\lambda _2}$$ = 6000 $$\mathop A\limits^ \circ $$ is

A linear aperture whose width is 0.02 cm is placed immediately in front of a lens of focal length 60 cm. The aparture is illuminated normally by a parallel beam of wavelength 5 $$ \times $$ 10^$$-$$5 cm. The distance of the first dark band of the diffraction pattern from the centre of the screen is

The interference pattern is obtained with two coherent light sources of intensity ratio n. In the interference pattern, the ratio $${{{I_{max}} - {I_{\min }}} \over {{I_{max}} + {I_{min}}}}$$ will be

The intensity at the maximum in a Young's double slit experiment is $$I$$₀. Distance between two slits is d = 5$$\lambda $$, where $$\lambda $$ is the wavelength of light used in the expreriment. What will be the intensity in front of one of the slits on the screen placed at a distance D = 10d ?