1. AMU PAST PAPERSPHYSICS- UNSOLVED PAPER -2001

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 In a Youngs double slit experiment, the separation on the two slits is doubled. The keep the same spacing of fringes, the distance D of the screen from the screen from the slits would be made : a. 2D b. DD c. 2D d. 4 4. 02 Problem The Hubble constant has the dimension of : a. Time b. (time)-1 c. length d. mass 5. 03 Problem The radius of a nucleus of mass number A is directly proportional to : a. A1/3 b. A2/3 c. A3 d. A3/2 6. 04 Problem A 60 kg man runs up a stair case in 12 second while a 50 kg man runs up the same stair case in 11 seconds. The ratio of the rate of doing their work will be : a. 10 : 11 b. 11 : 10 c. 6 : 5 d. 5 : 6 7. 05 Problem Two SHW are represented by the equation y 1 10 sin 3 t m y2 5(sin3 t 3 cos 3 t )4 their amplitude ratio, and phase difference are respectively : a. 1 : 1, 12 b. 2 : 3, 3 c. 3 : 4, 4 2 d. 2 : 1,7 8. 06 Problem Where A is the area of cross-section of spring and L is the length of the spring and E is the Youngs modulus of the material of the spring then time period and force constant of the spring will be respectively : a.EA LT 2,k MLEA b.1 EAAT ,k 2 MLEL 1 EAEA c. T ,k 2 MLL MLEA d. T 2,k EA L 9. 07 Problem A 4i ji j 4 4k and B 3 4k then angle between vectors is : a. 1800 b. 900 c. 450 d. 00 10. 08 Problem The deceleration experienced by a moving motor boat, after its engine is cut offd is given kv 3 where k is constant and is the magnitude of the velocity dt at time t after the cut off is : a. 0 c kt 0 b.20 kt 12 c. 00 d.2 11. 09 Problem The time displacement curves of two objects A and B are shown in the adjoining figure then : a. The graph does not give information b. Both A and B have same velocity c. The velocity of A is greater than B d. The velocity of A is less than B 12. 10 Problem The vectors j P ai aj 3k and Q ai 2 k are perpendicular to each other. The positive value of a is ; a. 13 b. 9 c. 4 d. 3 13. 11 Problem Consider the following statements : (i) For a permanent magnet the area of a hysteresis loop can be allowed to be large (ii) Coercivity of the material in permanent magnets should be small a. (i) but not (ii) b. (ii) but not (i) c. both (i) and (ii) d. neither (i) or (ii) 14. 12 Problem When pure germanium is doped with pentavalent impurity like phosphorus the conduction is due to : a. Position b. Protons c. Holes d. Electrons 15. 13 Problem Two capacitors of 10 F and 20 F are connected in series with a 30V battery. ?The charge on the capacitors will be respectively : a. 100 C, 100 C b. 200 C, 100 C c. 200 C, 200 C d. 100 C, 200 C 16. 14 Problem Intrinsic semiconductor is electrically neutral, extrinsic semiconductor having large number of current carriers would be : a. Electrically neutral b. Positively charged or negatively charged depending upon the type ofimpurity that has been added c. The positively charged d. Negatively charged 17. 15 Problem1 The amount of a radio active material 16th of its initial value in 28 days. Its mean life is approximately : a. 3.5 days b. 10 days c. 5 days d. 7 days 18. 16 Problem An observer sees two particles A and B approaching each other from opposite direction, each with a speed 0.8 C. The speed of particle B relative to A will be : a. 0.975 C b. 0.875 C c. 9.75 C d. 97.5 C 19. 17 Problem What is the energy equivalence to 1 g of coal ? a. 9 x 1010 J b. 8 x 1011 J c. 9 x 1012 J d. 9 x 1013 J 20. 18 Problem A proton and an -particle are accelerated through the same kinetic energy. The ratio of their de Broglie wavelength is : a. 4 : 1 b. 2 : 1 c. 1 : 1 d. 2 :1 21. 19 Problem The capacitance of spherical conductor is given by : a. C = 4 0 b. C = 40R2 1 c. C = 4 0 R d. C = 4 0 R 22. 20 Problem In an A.C. circuit the potential difference and current are represented respectively by V = 100 sin (100t) volt i = 100 sin 100t 3 milliamperes. The power in the circuit is : a. 2.5 watt b. 5 watt c. 10 watt d. 104 watt 23. 21 Problem Light of frequency 1.5 times the threshold frequency is incident on photo sensitive material. If the frequency is halved and intensity is doubled. The photoelectron becomes : a. Halved b. Quadrupled c. Zero d. Doubled 24. 22 Problem An electron moving with velocity 2 x 107 m/s describes a circle in a magnetic field of strength 2 x 10-2 tesla. If e/m of electron is 1.76 x 1011 C/kg. Then the diameter of the circle will be : a. 11 cm b. 1.1 cm c. 1.1 mm d. 1.1m 25. 23 Problem The range of wavelength of the visible part of the electro magnetic spectrum is : a. 8500 10000 b. 7000 8500 c. 3000 4000 d. 4000 7000 26. 24 Problem A TV transmitting tower has height of 160 m. Its covering range, and the height raised to double its covering range, will be respectively : a. 45 km, 640 m b. 50 km, 700 m c. 40 km, 600 m d. none of these 27. 25 Problem The stopping potential V0 virsus frequency plot of a substance is shown in fig. The thresold wavelength is : a. Cannot be estimated from given data b. 5 x 1014 cm c. 500 d. 6000 28. 26 Problem In an A.C. circuit resistance R, inductance L and capacitance C are in parallel. The value of R is 50 , inductive reactance XL = 40 and capacitive reactance XC = 25 . Then the reading of ammeter will be: a. 10.2 A b. 5 A c. 17 A d. 7 A 29. 27 Problem A conducting circlar loop is placed in a uniform magnetic field of 0.02 tesla with its palne perpendicular to the magnetic field. If the radius of the loop starts striking at a constant rate of 1 mm/s. Then the emf induced in the loop at the instant when the radius is a 4 cm will be : a. 8 V b. 5.0 V c. 2.0 V d. 2.5 V 30. 28 Problem Two inductors 0.4 H and 0.6 H are connected in parallel. If this combination is connected in series with an inductor of inductance 0.76 H. The equivalent inductance of the circuit will be : a. 0.1 H b. 0.2 H c. 1 H d. 2 H 31. 29 Problem The relation of magnetic force between two short magnets when they are coaxial will be : a. F 0 3M1M2 24r 0 3M1M2 b. F 4H r 416M1M2 c. 40 r40 6M1M2 d. 4 r4 32. 30 Problem the magnetic field at P on the axis of a solenoid having 100 turns / metre and carrying a current of 5 A is : a. 250 0 b. 5002 0 c. 500 0 d. 2502 33. 31 Problem A cylindrical container is filled with water upto top. It is a square hole of side L at a depth y from the top. Also there is a circular hole of radius R = L at a depth 2y from the top. Then the ratio of quantities of liquid flowing out through the two holes : 2 a.1 b.2 1 c. 2 1 d.2 34. 32 Problem A boy has 60 kg wt. He wants to swim in a river with the help of a wooden log. If relative density of wood is 0.6. What is the minimum volume of wooden log ? (density of river water is 1000 kg/m3) a. 0.66 m3 b. 150 m33 c. 1m3 3 d.m320 35. 33 Problem Four particles have speed 1 m/s, 2 m/s, 3 m/s and 4 m/s. The root mean square velocity of the molecule is : a. 2.74 m/s b. 2 m/s c. 1.37 m/s d. 5.48 m/s 36. 34 Problem In an isobaric process of an ideal gas. The ratio of heat supplied and work done Q by the system i.e., is : W a. 1 r b. c. 1 d. 1 37. 35 Problem The disc of siren has n holes and the frequency of its rotation is 300 rpm. It produces a note of wavelength 2.4 m. When the velocity of sound in air is 360 m/s. The value of n is : a. 24 b. 36 c. 5 d. 30 38. 36 Problem the minimum distance of a sounding body form the hill for heating echo clearly is : (speed of sound = 34 m/s) a. 270 m b. 8.5 m c. 34 m d. 17 m 39. 37 Problem A lens of camera has an aperture of 5 cm and focal length 14 cm . What is the f number of camera ? a. 19 5 b.14 c. 2.8 d. 70 40. 38 Problem An automobile of mass m is crossing over a concave over bridge with speed . If radius of bridge is R. The thrust on the bridge at the lowest point will be : m 2 a. Mg +R m 2 b. mg -R c. Mgm 2 d.R 41. 39 Problem From a water fall, water is falling down at the rate of 500 kg/s on the plates of a turbine. If the height of the fall is 50 m, then the power delivered to the turbine is nearly equal to : a. 2.5 kW b. 250 kW c. 10 kW d. 25 kW 42. 40 Problem A aeroplane is flying in a horizontal direction with a velocity u and at a height of 2000 m. When it is vertically below a point a on the ground at point B. If AB = 3 km and g = 10 m/s2. The value of u is : a. 300 km/hr b. 150 km/hr c. 540 km/hr d. 54 km/hr 43. 41 Problem A boat full of iron scrap is floating on water in lake. If all the iron is dropped into water, the water level of water : a. Go up b. Remain the same c. Rise very high d. Go very 44. 42 Problem The terminal potential difference of cell when short circuited, is : a. EE b. 2 c. E3 d. zero 45. 43 Problem A charged particle moving in a magnetic field is increased in its velocity, then its radius of the circle : a. Decreases b. Increases c. Remain same d. Becomes half 46. 44 Problem An electron revolves 6 x 1015 time per second in a circular orbit. The current in the loop is : a. 0.96 mA b. 0.96 A c. 28.8 A d. none of these 47. 45 Problem The value of Faradays constant is : a. 9.65 x 104 coulomb b. 9.65 x 104 coulomb c. 6.03 x 1027 coulomb d. 1.6 x 10-19 coulomb 48. 46 Problem If the coefficient of linear expansion of a solid is 0.00009, its coefficient of volume expansion is : a. 0.0009 b. 0.00018 c. 0.00027 d. 0.0003 49. 47 Problem Soldering of two metals is possible because of the property of : a. Viscosity b. Surface tension c. Osmosis d. Cohesion 50. 48 Problem When a triode is used as an amplifier the phase difference between the input signal voltage and output is : a. Zero b. c. 2 d. 3 51. 49 Problem For Balmer series that lies in the visible region, the shortest wavelength corresponds to quantum number : a. n =1 b. n = 2 c. n=3 d. n = 52. 50 Problem A double convex lens ( = 3/2) of focal length 20 cm is totally immersed in water ( = 4/3). Its focal length now will be : a. 20 cm b. 80 cm c. 40 cm d. 10 cm 53. 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