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)` .

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 Young's expriment, interference bands are produced on the screen placed at 1.5 m from the two slits 0.15 mm apart and illuminated by a light of wavelength 6500 overset (@)(A) . Find a) the fringe width and b) the change in the fringe width if the screen is taken away from the slit by 50 cm.

A point object is situated in air at a distance of 20 cm from a convex refracting surface of 5cm radius. The position of the image is [ mu=1.5]

In Young's double slit experiment , the distance between two slits is 0.1 mm . The distance between the screen and slits is 20 cm . If the slit is illuminated by a light of wavelength 5460 overset (@)(A) then the angular position of the first dark fringe is

In biprism experiment ,the eyepiece is placed at a distance of 1.2 metre from the sources.The distance between the virtual sources was found to be 7.5 xx 10^-4 m.Find the wavelength of light if the eye piece is to be moved transversely through a distance of 1.888 cm for 20 fringes.

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.

Two circles with diameters 6 cm and 9 cm touch each other externally.Find the distance between their centres.

Two point charges of 5muC and 15 muC are placed in air 20cm apart. Find the electric potential at the middle point of the line joining the two charges.

An arrow of 2.5 cm height is placed at a distance of 25 cm from a diverging mirror of focal length 20 cm. Find the nature, poistion and size of the image formed.

In single slit diffraction a = 0.14 mm, D = 2 m and distance of second dark band from central maxima is 1.6 cm . The wavelength of light is