CBSE Physics Model Practice Question Paper- 2
1. In a plane at 45° to the magnetic meridian the apparent dip is 30°. What is the true dip?
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2. When the plates of a charged parallel plate capacitor are brought closer to each other, how will their potential difference change?
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3. Differentiate between e.m.f. and potential difference in an electric circuit?
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4. Draw a typical magnetisation curve for a ferromagnetic para/dia magnetic material.
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5. What is 21 cm electromagnetic radiation? To which part of the em spectrum it belongs.
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6. Write the expression for the frequency of the AC output from an RC oscillator.
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7. The reading of the galvanometer G in the figure is zero. Calculate the value of R.
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8. Write the approximate orbital period of Venus.
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9. A positive charge q is placed in front of a conducting solid sphere at a distance r from its centre. Is there any electric field at the centre of the sphere due to the charges appearing in its surface? If so calculate the magnitude and direction of the field.
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10. A capacitor is charged by connecting it to a battery through a resistance. Find expressions for the energy stored in the capacitor and for the energy dissipated as heat in the resistor at any instant.
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11. In an electroplating experiment m gram of silver is deposited with 4A of current flow for 2 minutes. What is the amount of silver deposited by 6A in 40 sec?
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12. Each resistance in the network shown is r. What is the equivalent resistance between the points a and b.
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13. Along wire is bent so as to form a right angle at the middle. A current i is passed through the wire. What are the magnitudes of the magnetic fields at a and b?
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14. Why power is transmitted at very high voltages?
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15. A compound microscope of tube length 6,5 cm has a magnifying power of 100 when the finai image is formed at infinity. The focal length of the eye piece is 2 cm. What is the focal length of the objective?
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16. A converging lens of focal length 12 cm and a convex mirror of focal length 7.5 cm are placed 5.0 cm apart with their axes coinciding. An object is placed 60 cm from the lens away from the mirror. Where is the image formed? Answer
17. Show by diagrams the motion of a positive and a negative particle entering a magnetic field perpendicularly.
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18. Give a method of determining the size of a star.
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19. Give an explanation for ferromagnetic behaviour of substances? How is it different from paramagnetism?
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20. In the circuit shown a voltmeter reads 3V when connected across 1500 Ω. What is the resistance of the voltmeter?
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21. What is the function of a starter in a heavy motor?
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22. In Young’s double slit experiment, how coherent sources are obtained? State
(i) The colour of the central bridge
(ii) The colour of the fringe next to central fringe when the above experiment is performed with white light. Why no completely dark fringe is obtained in this case.
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23. In a plane electromagnetic wave passing through space, write the expressions for (i) elecric field (ii) magnetic field (iii) electrical energy density
(iv) magnetic energy density. What is the frequency of electrical energy density?
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24. A beam of light propagates through a medium 1 and falls onto another medium 2 at an angle a. After that it propagates in medium 2 at an angle p. The wavelength of light in medium 1 is λ, what is the wavelength in medium 2?
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25. In a hydrogen spectrum find the wavelength that lies between 618 nm and 700 nm.
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26. Draw a logical circuit showing A , B + A . B and write its truth table.
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27. What is a saturated condition of a transistor? Under what conditions a transistor is saturated? Draw a CE characteristic in output circuit and show the saturated part of the characleristies.
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28. What is neutron separation energy V Obtain its value for 29Ca41.
How can the emission of p particles be explained? Why all nuclei do not emit β particles? Which element has the most stable nucleus? Why then not ail nuclei degenerate into that element?
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29. Describe Bohr’s theory of Hydrogen atom and find the expression for the frequency of 2nd line of Baimer series.
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30. In Geiger Marsden experiment define the terms, inpact? parameter, and the distance of closer approach. Illustrate your answer. A proton coming from infinity hits a proton at rest. The impact parameter is zero. The velocity v of the hitting proton is in the straight line connecting the centres of protons. The mass of the proton ism. Find the distance of closest approach.
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