1. AMU PAST PAPERSPHYSICS- UNSOLVED PAPER - 1996

2. SECTION I Single Correct Answer Type There are five parts in this question. Four choices are given for each part and one of them iscorrect. Indicate you choice of the correct answer for each part in your answer-book bywriting the letter (a), (b), (c) or (d) whichever is appropriate 3. 01 Problem The current amplification factor of a common base transistor and current amplification of a common emitter transistor are not related with: a. 11 1 b. 1 c. 1 d. 1 4. 02 Problem An extremely hot star would appear to be: a. Orange b. yellow c. Blue d. red 5. 03 Problem The magnetic flux density B at a distance r from a long straight wire carrying steady current varies r as shownin fig: a. b. c. d. 6. 04 Problem Which of the following material is paramagnetic? a. Aluminum b. water c. Copper d. Bismuth 7. 05 Problem The force F is given in terms of time t and displacement z by the equation: F=A cos Bx+C sin Dt The Dimensions of D/B are a. MLT-1 b. LT-2 c. L2T d. LT-1 8. 06 Problem The speed of light c, gravitational constant G and Plancks constant h are taken as fundamental units in a system. The dimensions of time in he new system should be: a. G+1/2H1/2c1/2 b. G1/2c-3/2h1/2 c. G-1/2h1/2c1/2 d. G-1/2h1/2c-5/2 9. 07 Problem A particle moves along a straight line such that its displacement at any time t is given by: s=t3-6t2+3t+4 The velocity, when its acceleration is zero, is a. -9m/s b. 22m/s c. 13m/s d. 2m/s 10. 08 Problem A particle moves along x-axis from x=0 to x=5 m under the influence of a Forse given by F=(7-2x+3x2) Newton. The work done in the process is: a. 135 j b. 270 j c. 67.5 j d. None of these 11. 09 Problem A constant force acts on a particle and its displacement x in metre is related to the time t in second by the equation: t= x 3 When the velocity of the particle is zero, its displacement is in cm: a. Zero b. 1 c. 5 d. 2 12. 10 Problem A bullet is fired from the gun, the force on the bullet is given by F= 600 - 2 x105t Where F is in Newton and t in second. The force on the bullet becomes zero as soon as it leaves the barrel. The average impulse imparted to the bullet will be: a. 1.5 Ns b. 0.9 Ns c. Zero d. 8 Ns 13. 11 Problem A body is projected horizontally from a point above the ground the motion of the body is described by the equation: x = 2t, y = 5t2 Where x, and y are in horizontal and vertical coordinates after time t. the initial velocity of the body will be : a. 29 m/s horizontal b. 5m/s horizontal c. 2m/s vertical d. 2m/s horizontal 14. 12 Problem A block of metal weighing 2 kg is resting on a frictionless plane. It is struck by a 1 kg/sec and at a speed of 5m/s. The initial acceleration of the blocks is: a. 7.5m/s2 b. 1.25m/s2 c. 5m/s2 d. 2.5m/s2 15. 13 Problem A uniform chain of length L and mass M is lying on a smooth table with one fourth of it hanging freely from the edge of the table. The amount of work required to pull the chain on the table is nmgl where n is equal to:1 a.21 b. 8 1 c. 121 d. 32 16. 14 Problem A satellite of mass m is orbiting the earth in a circular path of radius r with velocity v. How much energy is required to take the satellite from an orbit of radius r to the satellite from an orbet of radius r to 3r ?GMm a. 3r2GMm b. 3rGMm c.rGMm d.2r 17. 15 Problem The masses and radii of earth and moon are M1,R2 and M2,R2 respectively. Their contres are at a distance d apart. the minimum speed with which the partical of mass m should be projected form a point midway between the two centers so, as to escape to infinity is:G(M1 M2 ) a.dG(M1 M2 ) b. 2d2G(M1 M2 ) c. d G(M1 M2 ) d. 2d 18. 16 Problem A bimetallic strip, consisting of iron and brass is heated. It bens into an are with iron on concave side and brass on convex side of the arc. This is because: a. It is more difficult to bend brass rod than an iron rod b. Brass has a higher coefficient of linear expansion than iron. c. Density of iron is lower than that of brass d. The specific heat of iron is lower than that of brass. 19. 17 Problem A balloon of volume 1500 m3 and weighing 1650 kg with all its equipment is filled with helium (density 0.2 kg/m3). If the density of air be 1.3 kg/m3. the pull on the rope tied to the balloon will be: a. 1950 kg b. 16600 kg c. 300 kg d. Zero 20. 18 Problem The root mean square velocity (rms) of hydrogen molecule at 300 K is 1930 m/3. The value of rms velocity of oxygen molecules at 1200 K, will be: a. 965 m/s b. 1065 m/s c. 865 m/s d. None of these 21. 19 Problem N molecules each of mass m of a gas A and 2N molecules each of mass 2 m of a gas B are contained in the same vessel which are maintained at a temperature T. The mean square velocity of the molecule of B type is denoted by v2 and the mean square of the X-component of the velocity of A type is denoted by 2 then the value of 2 will be: 2 v a. 2/3 b. 3/2 c. 1/3 d. 22. 20 Problem Water falls through a height of 250 m. Assuming that whole of energy due to fall is converted into heat. The rise in temperature of water (g =9.8m/s2,j =4.18x103 j/ kilocal) : a. 3.590c b. 2.590c c. 1.590c d. 0.590c 23. 21 Problem Two bodies A and B of the same mass are suspended from two separate springs of spring constant K1 and k2 respectively. The two bodies oiscillate vertically and they have the same maximum acceleration. The amplitude of oscillation of A and B are in the ratio of: k1 a.k22k2 b.k1k1 2 k2 c. k2 d.k1 24. 22 Problem One tesla is not equal to: a. 1J/A b. 104 gauss c. 1wb/m2 d. 1 J/Am2 25. 23 Problem The frequency of revolution of a charged particle in a magnetic field is independent of: a. Strength of magnetic field b. Speed of the particle c. Change of particle d. None of these 26. 24 Problem A transformer is used to reduce the main supply of 220 V to 11 volt. If the currents In the primary and secondary are 5A and 70A respectively. The efficiency of the transformer: a. 45 % b. 50 % c. 75 % d. 90 % 27. 25 Problem If the earth were to loss its atmosphere, then compared to the previous average temperature of its surface, then the temperature would: a. Be unpredictable b. Remain constant c. Decrease d. Increase 28. 26 Problem A proton and an particle are accelerated though the same potential difference. The ratio of their de Broglie wavelength ( p/ a) is:1 a. 8 b. 8 c. 1 d. 2 29. 27 Problem In which of the following region, the Lyman series are found? a. Infrared b. Visible c. Both (a)and (b) d. Ultraviolet 30. 28 Problem The order of density of nuclear matter is: a. 1017 kg/m3 b. 1019 kg/m3 c. 1034 kg/m3 d. 1021 kg/m3 31. 29 Problem In a thermonuclear reaction 2 2 2 4 1 1H +1H +1H 2He +1H+0n1+21.6MeV. The percentage of mass converted into energy, will be: a. 3.39 % b. 2.39 % c. 1.39 % d. 0.39 % 32. 30 Problem One serious drawback of semiconductor devices is : a. They pollute the environment b. They can not be used with high voltage c. They are costly d. They do not last for long time 33. 31 Problem The minimum number of artificial satellite needed to be placed to the surface of earth for worldwide communication between any two location is a. 6 b. 4 c. 3 d. 2 34. 32 Problem What is the voltage gain in a common emitter amplifier, when in put resistance is 3 and the load resistance 24 with =60? a. 480 b. 240 c. 48 d. 4.8 35. 33 Problem A light ray is incident on a prism in minimum deviation of 340.if the shaded half of the prism is removed off, then the same ray will suffer a deviation of : a. 00 b. 650 c. 170 d. 340 36. 34 Problem In a youngs double slit experiment the angular width of a fringe formed on a distant screen is 0.10. The wavelength of light used is 6000A0.The spacing between the slits is : a. 1.72 10--4 m b. 3.44 10-4 m c. 6.88 10-4m d. None of these. 37. 35 Problem A car blowing a horn of frequency 700Hz is going at a speed of 2 m/s towards a vertical wall. If the speed of sound in air is 352 m/s.how many beats does the car driver hear every second? a. 8 b. 10 c. 9 d. 15 38. 36 Problem The ratio of specific heats at constant pressure and constant volume is 7/5 for hydrogen,5/3 for helium. The ratio of speed of sound in hydrogen to that of heliun at the same temperature and pressure is :42 a. 2542 b. 55 c. 2421 d. 5 39. 37 Problem Which graph represents the variation of speed of sound with temperature? a. b. c. d. 40. 38 Problem The equation of plane progressive wave is y = 4 sin (100t = 2x) Where x and y in cm and t in second. The maximum particle velocity is: a. 400 cm/s b. 100 m/s c. 200 m/s d. 400 m/sec 41. 39 Problem 7 g of nitrogen is mixed with 16 g of oxygen in tube and then sealed. The speed of sound in the tube at 270 is: a. 305 m/s b. 337.5 m/s c. 154 m/s d. None of these 42. 40 Problem The resistance of a galvanometer is 90 ohm. If only 10% of the main current may flow through the galvanometer in which way and in what way a resistor is to be used? a. 810 ohm in series b. 810 ohm in parallel c. 10 ohm in parallel d. 10 ohm in series 43. 41 Problem A solenoid 1.5 m long and 4.0 cm in diameter possess 10 turns/cm. A current of 5.0 ampere is flowing through it. Calculate the magnetic induction (i) inside and (ii) at one end, on the axis of solenoid: a. 2 x103 tesla, x103 tesla b. 0.5 x103 tesla, x 103 tesla 23 c. x 103 tesla, x 103 tesla23 d. None of these 44. 42 Problem Two small magnets each of magnetic moment 10 Am2 are placed in end on positions 0.1 m apart from their centres. The force acting between them is: a. 0.06 N b. 0.6 N c. 0.6 x 107 N d. 0.06 x 107 N 45. 43 Problem A condenser of capacity 1 F and a resistance 0.5 mega ohm are connected in series with a D.C. supply of 2V. The time constant of the circuit is: a. 0.25 sec b. 0.5 sec c. 1 sec d. 2 sec 46. 44 Problem In a series LCR circuit with a source of voltage 50V, frequency 50 Hz, R = 300, L = 1.0 H, C = 20 , the potential difference across the capacitor will be: a. 50V b. 30V c. 10V d. Zero 47. 45 Problem An electromagnetic radiation has an energy 14.4 keV. To which region of electromagnetic spectrum does it belong? a. X-ray region b. Ultra violet region c. Infrared region d. None of these 48. 46 Problem The kinetic energy of an electron which is accelerested through a potential difference of 100 V is: a. 6.626 x 10-3 watt sec b. 1.16 x 10-34 J c. 418.6 cal d. 1.6m x 10-17J 49. 47 Problem Which of the following graph represent correctly the variation of photoelectric current i with intensity I of incident radiations? a. b. c. d. 50. 48 Problem The wavelength of the first line of Lyman series of hydrogen is 1216 Ao. Wavelength of the second line of the same series is: a. 6566 b. 912 c. 1026 d. 912 51. 49 Problem A gamma ray photon of energy 2.2 MeV produces an electron position pair. What is the Kinetic Energy of pair of particles so produced? a. 1.18 MeV b. 2.36 MeV c. 0.18 MeV d. None of these 52. 50 Problem If 5 of U235 is completely destroyed in a reactor, the energy realeased would be: a. 60 x 1015 J b. 15 x 1010 J c. 45 x 1010 J d. 45 x 1013 J 53. FOR SOLUTIONS VISIT WWW.VASISTA.NET