Nature of Light Problems - Physics 11th - Chapter 9 - Sindh Textbook Board (stb problems)

 

NATURE OF LIGHT

(PROBLEMS)

Problem 9.1. How many fringes will pass a reference point if the mirror of a Michelson's interferometer is moved by 0.08 mm. The wavelength of light used is 5800Å.

Problem 9.2. In a double slit experiment the separation of the slits is 1.9 mm and the fringe spacing is 0.31mm at a distance of 1 metre from the slits. Find the wavelength of light?

Problem 9.3. Interference fringes were produced by two slits 0.25 mm apart on a screen 150 mm from the slits. If eight fringes occupy 2.62 mm. What is the wavelength of the light producing the fringes?

Problem 9.4. Green light of a wavelength 5400Å is diffracted by grating having 2000 line/cm. (a) Compute the angular deviation of the third order image. (b) Is a 10th order image possible?

Problem 9.5. Light of a wavelength 6 × 10^−7m falls normally on a diffraction grating with 400 lines per mm. At what angle to the normal are the 1st, 2nd and 3rd order spectra produced?

Problem 9.6. If a diffraction grating produced a 1st order spectrum of light of wavelength 6 x 10^-7m at an angle of 20° from the normal. What is its spacing and also calculate the number of lines per mm?

Problem 9.7. Newton's rings are formed between a lens and a flat glass surface of wavelength 5.88 × 10^−7m. If the light passes through the gab at 30° to the vertical and the fifth dark ring is of diameter 9 mm. What is the radius of the curvature of the lens?

Problem 9.8. How far apart are the diffracting planes in a NaCl crystal for which X-rays of wavelength 1.54A make a glancing angle of 15° - 54' in the 1st order?

Problem 9.9. A parallel beam of X-rays is diffracted by rocksalt crystal the 1st order maximum being obtained when the glancing angle of incidence is 6 degree and 5 minutes. The distance between the atomic planes of the crystal is 2.8 x 10^-10m. Calculate the wavelength of the radiation.