CBSE Physics Model Question Paper- VI
1. Why two electric lines of force never intersect each other?
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2. What is the difference between voltmeter and voltameter?
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3. Write down truth table for NOR gate.
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4. What is the use of control rods? Of what material are these usually made?
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5. Nature is using fusion reaction somewhere. Name it.
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6. What is meant by blue shift?
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7. Give two properties common to whole of e.m. spectra.
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8. What is solar cell?
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9. What is meant by dielectric polarisation ? Define dielectric constant of a medium.
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10. What is magnetic susceptibility? How does it vary in case of a paramagnetic substance?
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11. What is figure of merit? How is it determined?
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12. What is Seebeck effect and Seebeck coefficient?
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13. Range of an ammeter has to be increased N times. How can it be done?
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14. What is the ratio of gravitational and electrical forces of attraction between a proton and an electron?
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15. What are the conditions of sustained interference?
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16. State 2 main advantages and two disadvantages of semiconductors.
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17. Derive an expression for total work done in rotating an electric dipole through an angle 6 in a uniform magnetic field.
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18. What is Brewster’s law? What conclusions can be drawn from it?
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19. Derive an expression for a force on a current carrying conductor placed in a uniform magnetic field.
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20. A100 W, 250 V and a 50 W, 250 V lamps are connected in series. The combination is connected to 250 V supply. Which lamp will glow brighter? Justify your answer with proper calculations.
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21. You are having three mirrors fixed in the wall. Without touching these with anything, how can you say which one is plane, convex or concave?
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22. Positive terminals of 2 cells of 2 V, internal resistance of 1Ω and 1V, internal resistance 2 Ω are connected through 10 Ω wire, the negative terminals are connected through 8 Ω wire. The mid point of 10 Ω and 8 Ω wire are joined by 4 Ω wire. Find the current and P.D. across 4 Ω wire. Also find terminal P.D. across each cell.
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23. How can you derive the intensity at a point on neutral axis of a dipole? How the relation gets modified for small dipoles?
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24. How can the size of a star be determined from the knowledge of luminousuy of a star?
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25. What are elements of earth’s magnetic field? Define them. What is angle of dip on magnetic pole and magnetic equator? In which direction will a compass point in field free area?
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26. Describe Hertz experiment to confirm the existence of e.m. waves? Draw e.m. spectra.
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27. Four charges +q, + q, q, - q are placed respectively at the four corners of a square of side a. Find the magnitude and direction of electric field at the centre of the square.
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28. What are particle accelerators? Describe cyclotron. Why is cyclotron not suitable for accelerat¬ing electrons and neutrons?
Two slits 0.125 mm apart are illuminated by light of wavelength 4500 A. The screen is 1 m away from the plain of the slits. Find the seperation between second bright fringe and 4th dark fringe.
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29. What is fusion and fission of nuclei? Can these be used for peaceful purposes? What were the maximum and least powers of nucelar devices exploded by India on 11th and 13th May 1998?
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30. What is Gauss’s theorem? Deduce the expression for electric intensity outside, on and inside a charged solid sphere.
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