SECTION - A
Note: a) Answer all questions. b) Every question carries 2 marks.
c) All are very short answer type questions. 10 x 2 = 20
1. An obstacle such as a telephone pole can cast a shadow in the light from a distant source. No such effect is noticed for the sound from a distant car. Why?
2. Two waves of same frequency have amplitudes 1.00 and 2.00. They interfere at a point where their phase difference is 60.0°. What is the resultant amplitude at that point?
3. On what factors does the period of oscillation of a bar magnet in a uniform magnetic field depend?
4. Write the units of (i) Charge, (ii) Electric field strength, (iii) Electric potential and (iv) Capacitance.
5. State Ampere's Law and Biot - Savart's Law.
6. If a current of 2A is reduced to zero in 1/16 S, find the induced emf in an inductor of inductance 0.25 H.
7. If a proton and an electron have same de Broglie wavelength, which has more momentum and Kinetic energy?
8. If np and ne represent the concentrations of holes and free electrons respectively, what is the relation between them in (i) an intrinsic semi conductor and (ii) a p-type semiconductor.
9. Write the truth tables of (i) OR-gate and (ii) AND gate.
10. What are the basic blocks of communication system?
SECTION - B
Note: a) Answer any six questions. b) Every question carries 4 marks.
c) All are short answer type questions. 6 x 4 = 24
11. Derive prism formula.
12. Derive an expression for the torque acting on a bar magnet in a uniform magnetic field and hence define 'magnetic moment'.
13. A capacitor of capacitance 10 μF is charged by a 12 V battery, while the battery is still present in the circuit, the space between the capacitor plates is filled with a dielectric of dielectric constant K = 3. Calculate the energy stored in the capacitor filled with dielectric.
14. The intensity of magnetic induction at the centre of a circular coil is B. What happens to it if the number of turns and radius are doubled?
15. Obtain an expression for the current through an inductor when an ac emf is applied.
16. Explain construction and working of Duddell's thermogalvanometer.
17. Describe Thomson's experiment to determine e/m of an electron with relevant theory.
18. Explain the working of a common emitter amplifier with necessary circuit diagram.
SECTION - C
Note: a) Answer any two questions. b) Each question carries 8 marks.
c) All are long answer type questions. 2 x 8 = 16
19. How are stationary waves formed in a closed pipe? Explain the various modes of vibrations in a closed pipe and establish the relation between their frequencies.
20. State and explain Kirchoff's Laws in electricity and apply them to Wheatstone bridge to obtain its balancing condition.
21. Explain the working of a nuclear reactor with the help of a labelled diagram.
A nuclear power reactor generates electric power of 100 MW. How many number of fissions occur per second if nuclear power used in the reactor is Uranium that generates an energy of 200 MeV per fission?