0Why does the intensity of the secondary maximum become less as compared to the central
maximum?
2. State the reason, why two independent sources of light cannot be considered as coherent
sources?
3. A biconvex lens has a focal length 2/3 times the radius of curvature of either surface. Calculate
the refractive index of lens material.
4. Draw a ray diagram of astronomical telescope in general adjustment. Write an expression
for its magnifying power.
5. Why does Sun appear reddish at Sun set or Sun rise?
6. Draw a labeled diagram of Newtonian type telescope. Write its one advantage over
refracting type telescope.
7. Derive the lens formula for biconvex lens. How is the approximate value of the focal length of
such a lens estimated in the laboratory?
8. An object is placed at (i) 10 cm; (ii) 5cm in front of a concave mirror of radius of curvature 15
cm. find the position, nature, and magnification of the image in each case.
9. State Huygens’s wave theory and using it prove the Snell’s law for refraction.
10. Derive an expression for magnifying power of compound microscope with a labeled diagram.
11.A compound microscope consists of an objective lens of focal length 2 cm and eyepiece of focal
length 6.25cm separated by a distance of 15 cm. How far from the objective should an object be
placed in order to obtain the final image at (a) the least distance of distinct vision (25cm), (b)
infinity? What is the magnifying power in each case?
12 Write the names of defects of human eye with ray diagram of their correction.
13 A right angled glass prism forms images of a small straight object which are deviated by (i) 900,
(ii) 1800 and (iii) 00.
14. State and prove Brewster’s law.
15. Explain an experiment with require diagram which show the transverse nature of light.
16. Derive and expression for the refraction by a convex refractive surface. Using it derive the Lens
Maker’s formula.
17. What is diffraction of light? Draw a graph showing the variation of intensity with angle in
a single slit diffraction experiment. Write one feature which distinguishes the observed
pattern from the single slit pattern from the double slit pattern. How would the diffraction
pattern of a single slit be affected when: (i) the width of the slit is decreased and (ii) The
monochromatic source of light is replaced by a source of white light?
