Optics Answers

A rectangular glass block (n=1.52) is placed inside a clean water contained in a basin. A layer of oil (n=1.44) floats on the water surface. A ray of light from air strikes the oil surface at an angle of incidence of 28° . Calculate the angle of refraction at the water-glass interface. (refractive index of air =1.00)

A helium-neon laser diffraction-limited light beam of wavelength 600 nm and diameter 3×10⁻³m is directed towards the surface of the moon 375×10³ km away.

To calculate the diameter of light patch produced on the moon.

A beam of light is incident at an angle of teta on one face of an equilateral triangular prism made from a material of refractive index 1.6. At what angle of refraction in the prism will the emerging ray graze the opposite face ? What is the time used when the light’s frequency is 4.3 x 10^14 Hz

A body moving in a progressive wave pattern has acceleration of 10cm/s² when the displacement is 6cm and a speed of 12cm/s² when the displacement is 8cm. What is the amplitude of the wave?

In a Newton's ring experiment, the diameter of the 10th ring changes from 1.40 cm to 1.27 cm when a liquid is introduced between the lens and the plate. To calculate the refractive index of the liquid.

The coherence length for sodium D₂ line is 2.5cm. To deduce the coherence time and spectral width of the line. Given wavelength of D₂ line=6000 angstrom.

A transparent filen of glass of refractive index 1.5 is introduced normally in the path of one of the interfering beams of a Michelson interferometer which is illuminated with a light of wavelength 4800 angstrom. This causes 500 dark fringes to sweep across the field. To determine the thickness of the film.

To calculate the angle of diffraction for red colour(λ=8000 angstrom)in the first order of spectrum for a grating with 14438 lines per inch.

Please explain pulse dispersion in step-index fibre. If the core and cladding refractive indices for a step-index fibre are 1.47 and 1.46 respectively, calculate the broadening of a pulse after a distance of 5 km.

a ray of light passes from air through a rectangular block of glass with parallel faces 6.5cm apart at an angle of incidence 35 degrees. calculate:
a) the angle of refraction
b) the lateral displacement