Optics Answers

A diffraction grating has 2000 lines. Two sources of monochromatic lights emanating wavelengths λ1 and λ2 are just resolved by the grating in the first order spectrum. If the mean of λ1 and λ2 is 600 nm, calculate the difference between the wavelengths.

A wedge shaped film has refractive index 1.34 and thickness of extreme sides 0 (zero) and t. If a light of wavelength 492 nm is incident normally on it and 20 fringes are obtained, determine t.

If the space between the lens and plane glass plate in the Newton's ring set up is filled with a liquid of refractive index 1.38 and the wavelength of light used is 580 nm, calculate the diameter of the 4th dark ring. Take the radius of curvature of the lens to be 0.75 m.

For normal incidence of light from a medium of refractive index 1.42 onto a medium of refractive index 1.64, calculate the reflection and transmission co-efficient.

The Bragg reflection angle from the (110) planes in bcc iron is 22° for an x-ray

beam with lemda= 1.54 Å. Calculate the lattice constant for iron (take n = 1).

A 74.2 kg skier is at rest at the top of a 268 m high run. The slope is inclined at a 24.4º angle relative to horizontal. How much kinetic energy does the skier have?

an object is placed in front of a converging lens of focal length 20cm, the image is virtual and has a magnification of 2. what is the distance of the object from the lens

In a double slit experiment two interference patterns are seen on the screen.One pattern is due to light of wavelength 500nm and second pattern is due to light of wavelength 400nm. The distance between the slits is 2.5mm and the distance of screen from slits is 1m . The separation on the screen between the fifth order (m=5) bright fringes of two interference patterns will be

Ans: 0.2mm

A 2.0cm high object is placed on the principle axis of concave mirror at a distance of 12cm from the pole.If the image is inverted real and 5.5cm high then the focal length of the mirror

A convex lens forms a real image of a point object at a distance of 50 cm from the convex lens lens of the image side on placing a plane Mirror on the image side and facing the convex and it is observed that the final image now concepts with objects itself the focal length of the concave lenses