## March 2, 2014

### Senior Inter Physics Model Paper - New Syllabus

SECTION - A
I. (i) Very Short Answer Type Questions.
(iii) Each question carries TWO marks. 10 × 2 = 20
1. Define focal length and radius of curvature of a concave lens.
2. The electric lines of force do not intersect. Why?
3. State Gauss's law in electrostatics.
4. A circular coil of radius 'r' having N turns carries a current 'i'. What is its
magnetic moment?
5. What happens to the compass needle at the earth poles?
6. The force between two magnet poles separated by a distance 'd' in air is 'F'.
At what distance between them does the force become doubled?
7. Write the expression for the reactance of ....
i) an inductor and ii) a capacitor.
8. Give two uses of infrared rays.
9. What is an n-type semiconductor? What are the majority and minority charge
carriers in it?
10. What is "World Wide Web" (www)?

SECTION - B

II. (i) Short Answer Type Questions.
(iii) Each question carries FOUR marks. 6 × 4 = 24

11. Explain the formation of a rainbow.
12. Derive the expression for the intensity at a point where interference of light
occurs. Arrive at the conditions for maximum and zero intensity.
13. Derive an expression for the capacitance of a parallel plate capacitor.
14. State and explain Ampere's law.
15. Describe the ways in which Eddy currents are used to advantage.
16. What is the effect of (i) intensity of light (ii) potential on photoelectric current?
17. What are the limitations of Bohr's theory of hydrogen atom?
18. What is rectification? Explain the working of a full wave rectifier.

SECTION - C

III. (i) Long Answer Type Questions.
(iii) Each question carries EIGHT marks. 2 × 8 = 16

19. (a) What is Doppler effect? Obtain an expression for the apparent frequency of
sound heard when the source is in motion with respect to an observer at rest.
(b) A rocket is moving at a speed of 200 ms−1 towards a stationary target. While
moving, it emits a wave of frequency 1000 Hz. Some of the sound reaching
the target gets reflected back to the rocket as an echo. Calculate ...
1) the frequency of sound detected by the target and
2) the frequency of the echo as detected by the rocket.
20. (a) State Kirchhoff's law for an electrical network. Using these laws deduce the
condition for balance in a Wheatstone bridge.
(b) Three resistors each of resistance 10 ohm are connected, in turn, to obtain
(i) minimum resistance
(ii) maximum resistance.
Compute
a) The effective resistance in each case.
b) The ratio of minimum to maximum resistance so obtained.
21. Explain the principle and working of a nuclear reactor with the help of a
labelled diagram.