TIME : 3 HRS
M.M : 70
Q. NOS. 1-5 ARE OF 1 MARK EACH
1. State Gauss’s theorem in electrostatics.
2. Name the units of conductance and conductivity.
3. What is the ratio of speed of X-rays to -rays in vacuum?
4. Name one phenomenon indicating the wave nature of light and one phenomenon
indicating its particle nature.
5. What is meant by half-life of a radioactive substance?
Q. NOS. 6 – 15 ARE OF 2 MARKS EACH
6. If 100 Joule of work must be done to move electric charges equal to 4 units from
a place, where potential is –10 volt to another place, where potential is ‘V’ volt,
find the value of V.
7. Show that the capacitance of an insulated spherical conductor is directly
proportional to the radius of the spherical conductor.
8. If each of the resistance in network, shown in figure is r, what is the resistance
between terminals A and B?
9. Show electromagnetic waves are transverse in nature.
10. If two slits in Young’s experiment have width ratio 1:4, deduce the ratio of
intensity at maxima and minima in interference pattern.
11. Draw a labeled ray diagram showing formation of image in a compound
12. A radioactive nucleus undergoes a series of decays according to the sequence
3 . If the mass number and atomic number of
A3 are 172 and 69 respectively, what is the mass number and atomic number of
13. Explain the behaviour of metals, insulators and semiconductors on the basis of
energy bands in solids.
14. What are the drawbacks of optical communication systems?
15. Explain the following terms:
b. Optical pumping.
Q. NOS. 16 - 25 ARE OF 3 MARKS EACH
16. Derive an expression for the electric field intensity at a point on the axial line of
an electric dipole.
27 drops of same size are charged at 220 V each. They coalesce to form a bigger
drop. Calculate the potential of the bigger drop.
17. State and prove Ampere’s circuital law.
18. Derive an expression for the average power consumed in an a.c. circuit? What is
the value of power factor for a purely resistive circuit.
19. Explain diffraction of light due to a single slit and formation of pattern of fringes
20. Deduce the laws of reflection on the basis of Huygen’s principle.
21. The work function of Sodium is 2.3 eV. What is the maximum kinetic energy of
photoelectrons, if a photon of wavelength 450 nm falls on the surface?
22. Calculate the binding energy of an Alpha particle in Mev, gives that
mp=1.007825u, mn =1.008665u. Mass of
helium nucleus = 4.002800u and 1u
= 931 MeV.
23. What Do you mean by AND gate? Explain how it can be realized with the help
of an electronic circuit?
24. Discuss the working of pnp transistor as amplifier in common emitter
configuration. Explain the various gains in output.
25. A TV tower has a height of 100m. How much population is covered by the TV
broadcast if the average population density around the tower is 1000 km-2. Given:
radius of earth = 6.37 106 m.
Q. NOS. 26 -28 ARE OF 5 MARKS EACH
26. What is Seeback effect? Explain its cause. Explain how thermoelectric power
changes with temperature and hence find neutral temperature?
A thin metallic wire of resistance 100 ohm is immersed in a calorimeter
containing 250g of water at 10oC and a current of 0.5 ampere is passed through it
for half an hour. If the water equivalent of calorimeter is 10g, find the rise of the
27. Discuss with the help of a neat and labeled diagram the construction, working and
theory of a moving coil galvanometer.
28. What is a transformer? Give its principle and working. Give its two losses.