12th PHYSICS
Home work
1. Derive lens maker’s formula
2. Derive the relation between object and image distance in terms of refractive index of the medium and the radius of curvature of the spherical surface OR derive the relation between n, u, v, & R.
3. Arrive at the expression for refractive index of material of prism in terms of angle of the prism and angle of minimum deviation.
4. (i)Why sun is red at rise and set?
(ii)Why sky is blue in color?
5. Draw and explain the ray diagram showing the image formation in a compound microscope and label the parts.
6. Draw and explain the ray diagram of a refracting telescope and label the parts.
7. Show that the de Broglie wavelength λ of electrons of energy K is given by the relation λ = h/(2mk)1/2.
8. In Davisson and Germer experiment, state the observation which led to
(i) show the wave nature of electron, and
(ii)confirm the de Broglie’s relation.
9. Deduce the laws of reflection on the basis of Huygen’s wave theory.
10.Prove that the fringe width of both the bright and dark fringes in interface is same in Young’s double slit experiment.
11. Draw a sketch showing the incident, reflected and transmitted rays when the light is incident at the polarizing angle on a glass slab.
12.How would the angular separation of interference fringes in Young’s double slit’s experiment change when the distance of separation between the slits and the screen is doubled.
13. What type of wavefront will emerge from a (i) point source, and (ii) distant light source.
14. In a Young’s double slit experiment, the slits are separated by 0.28mm and the screen is placed 1.4m away. The distance between the central bright fridge and the forth bright fringe is measured to be 1.2cm. Determine the wavelength of light used in the experiment.
15. A compound microscope consists of an objective lens of focal length 2.0cm and an eyepiece of focal length 6.25cm separated by a distance of 15cm. How far from the objective should an object be placed in order to obtain the final image at (i)of distinct vision (25 cm),(ii) infinity? What is the magnifying power in each case?