The distance between the first and the sixth bright fringes formed in Young’s double slit experiment (measured by a spectrometer) is found to be 12.5 mm. The separation between the slits is 0.12 mm and the distance of the screen from the slits is 60 cm. Calculate :
(i) the fringe width
(ii) the wavelength of the light used (in nm).
(i) Given,
x6 - x1= 12.5 mm = 12.5 x 10-3 m
ii)
Wavelength,
Here,
d = 0.12 mm = 0.12 x 10-3 m
D = 60 cm = 0.6 m
Therefore,
(i) What is the difference between the electric field vector E at any point in the path of a linearly polarized light and that of an un-polarized light ?
(ii) Briefly describe how a given beam of light can be analysed and determined if it is linearly polarized or un-polarized.
A plano-convex lens made of glass (n = 1 5) has a focal length 10.0 cm.
(i) Calculate the radius of curvature of its curved surface.
(ii) If an identical plano-convex lens is placed in contact with the first (plane surfaces facing each other), what will be the power of the combination (in dioptres) ?
(i) State the three conditions for the formation of a pure spectrum.
(ii) Draw the ray diagram illustrating the measurement of the angle of a prism using a spectrometer.
The work function for sodium is 2.28 eV. [3]
(i) What is the minimum energy for a quantum of radiation to cause photoelectric emission from a sodium surface ?
(ii) Calculate the wavelength of this radiation.