For the same objective ,find the ratio of the least separation between two points to be distinguished by a microscope for light of `5000 overset (@)(A)` and electrons accelerated through 100 V used as the illuminating substance.

What is the minimum distance between two objects which can be resolved by a microscope having the visual angle of 30^@ when light of wavelength 500 nm is used ?

In a biprism experiment , the distance between the slit and the focal plane of the eyepiece is 1.2 m and the wavelength of light used is 5000 overset (@)(A) . When a convex lens is interposed (between the biprism and eyepiece) the images of the slits in the two positions are 5 mm and 1.8 mm apart . The distance between the centre of the pattern and twelfth dark band is

In Young's experiment , interference bands are produced on the screen placed at 1.5 m from the two slits separated by a distance of 0.15 mm and illuminated by a light of wavelength 4500 overset (@)(A) . Find the change in fringe width if screen is brought towards the slit by 50 cm .

In a biprism experiment the distance between the slit and the eyepiece is 100 cm. When a convex lens is introduced between the biprism and the eyepiece, images of the slit obtained in the two positions of the lens are 2 xx 10^-3 m and 4.5 xx 10^-3m apart.If the wavelength of light used is 6000 overset (@)(A) , find the distance between the fourth bright band on one side and fourth dark band on the other side of central bright band.

A point is situated at 6.5 cm and 6.65 cm from two coherent sources . Find the nature of illumination at the point if wavelength of light is 5000 overset (@)(A) .

The semivertical angle of a cone of the rays incident on the objective of the microscope is 20^@ . If lambda = 6600 overset@A , calculate the smallest distance between two points which can be just resolved.

Two straight and narrow parallel slits separated by 3mm are illuminated by a monochromatic light of wavelength 5460 overset (@)(A) . Interference fringes are obtained at a distance of 60 cm from the slits. Find the change in fringe width if the distance between the slits is i) increased by 1 mm and ii) decreased by 1mm.

In an optics experiment, with the position of the object fixed, a student varies the position of a convex lens and for each position, the screen is adjusted to get a clear image of the object. A graph between the object distance u and the image distance v, from the lens, is plitted using the same scale for the two axes. A straight line passing through the origin and making an angle of 45^circ with x-axis meets the experimental curve at P. The coordinates of P will be.

The vertical angle subtended by two points on a glass block at the objective of a microscope is 20^@ .Calculate the minimum distance between the points if they are just resolved when illuminated by light of wavelength 600 nm. What is the increase in resolving power of the instrument if the objective is immersed in oil of refractive index 1.5?