1. aipmt–Past papers PHYSICS- UNSOLVED PAPER - 2007

2. SECTION – I (Total Marks : 50) Single Correct Answer Type There are five parts in this question. Four choices are given for each part and one of them is correct. Indicate you choice of the correct answer for each part in your answer-book by writing the letter (a), (b), (c) or (d) whichever is appropriate .

3. 01 Problem The primary & secondary coils of a transformer have 50 & 1500 turns respectively. If the magnetic flux linked with the primary coil is given by , where is the webers, t is time in seconds & is a constant, the output voltage across the secondary coil is 120 volts 220 volts 30 volts 90 volts

4. Problem 02 A beam of electron passes undeflected through mutually perpendicular electric & magnetic fields. If the electric field is switch off, & the same magnetic field is maintain, the electrons move In a circular orbit Along a parabolic path Along a straight line In an elliptical orbit.

5. Problem 03 The position x of a particle with respect to time t along x-axis is given by where x is in meters & t in second. What will be the position of this particle when it achieves maximum speed along the +x direction? 54m 81m 24m 32m

6. Problem 04 A particle starting from the origin (0, 0) moves in a straight line in the (x,y) plane. Its coordinates at a later time are , 3). The path of the particle make with the x-axis an angle of a. b. c. d.

7. Problem 05 A car move from X to Y with a uniform speed & returns to Y with a uniform speed . The average speed for this round trip is a. b. c. d.

8. Problem 06 Two radioactive substance A & B have decay constants respectively. At t=0 they have the same number of nuclei. The ratio of number of nuclei of A to those of B will be after the time interval a. b. c. d.

9. Problem 07 In the following circuit, the output y for all possible inputs a and B is expressed by the truth table. a. A B Y 0 0 1 0 1 1 1 0 1 1 1 0 b. A B Y 0 0 1 0 1 0 1 0 0 1 1 0

10. Problem c. A B Y 0 0 0 0 1 1 1 0 1 1 1 1 d. A B Y 0 0 0 0 1 0 1 0 0 1 1 1

11. Problem 08 In a radioactive decay process, the negatively charged emitted - particle are The electron produce as a result of the decay of neutrons inside the nucleus The electron produce as a result of the collision of the atoms The electron orbiting around the nucleus The electron present inside the nucleus

12. Problem 09 The phase difference between the instantaneous velocity & acceleration of a particle executing simple harmonic motion is π 0.70π 0 0.5π

13. Problem 10 In a mass spectrometer used for the measuring the mass of ions, the ions are initially accelerated by the electric potential V & then made to describe semicircular paths of radius R using a magnetic field B. if V & B are kept constant, the ratio will be proportional to a. b. c. R d. 1/R

14. Problem 11 A wheel has an angular acceleration of 3.0 rad/ & an initial angular speed of 2.00 rad/sec. in a time of 2sec it is rotated through an angle (in radian) of 10 12 4 6

15. Problem 12 A hollow cylinder has a charge q coulomb within it. If is the electrical flux in unites of voltmeter associated with the curved surface B, the flux linked with the plane surface A in unites of voltmeter will be a. b. c. d.

16. Problem 13 The frequency of the light wave in a material is & wavelength is .The refractive index of material will be 1.50 3.00 1.33 1.40

17. Problem 14 A nucleus has mass represented by M(A,Z). If denotes the mass of proton & neutron respectively & B.E the binding energy in MeV, then a. b. c. d.

18. Problem 15 The total power dissipated in watt in the circuit shown here is 40 54 4 16

19. Problem 16 If the nucleus has a nuclear radius of about 3.6fm, then Te would have its radius approximately as 9.6fm 12.0 fm 4.8 fm 6.0 fm

20. Problem 17 A block B is pushed momentarily along a horizontal surface with an initial velocity V. if is the coefficient of sliding friction between B & the surface, block B will come to rest after a time a. b. g/V c. V/g d.

21. Problem 18 A particle moving along the x-axis has acceleration f, at time t, given by , where f0 & T are constant. The particle at t=0 has zero velocity. In the time interval between t=0 & the instant when f=0, the particle’s velocity is a. b. c. d.

22. Problem 19 A common emitter amplifier has a voltage gain of 50, an input impedance of & an output impedance of . The power gain of the amplifier is 1000 1250 100 500

23. Problem 20 Three resistance P, Q, R each of & an unknown resistance S form the four arms of a Wheatstone bridge circuit. When a resistance of is connected in parallel to S the bridge get balanced. What is the value of S? a. b. c. d.

24. Problem 21 A steady current of 1.5 amp flows through a copper voltmeter for 10min. if the electro chemical equivalent of copper is the mass of copper deposited on the electrode will be 0.50 g 0.67 g 0.27 g 0.40 g

25. Problem 22 A small coin is resisting on the bottom of a beaker filled with a liquid. A ray of light from the coin travels upto the surface of the liquid & moves along its surface. How fast is the light travelling in the liquid? a. b. c. d.

26. Problem 23 A transformer is used to a light a 100W & 110V lamp from a 220V mains. If the main current is 0.5amp, the efficiency of the transformer is approximately a.50% b.90% c.10% d. 30%

27. Problem 24 Dimension of resistance in an electric circuit, in term of dimension of mass M, of length L, of time T & of current I, would be a. b. c. d.

28. Problem 25 A uniform rod AB of length l & mass m is free to rotate about point A. the rod released from rest in the horizontal position. Given that the moment of inertia of the rod about A is , the initial angular acceleration of the rod will be a. Mgl/2 b. c. d.

29. Problem 26 A particle of mass m moves in the XY plane with a velocity v along the straight line AB. If the angular momentum of the particle with respect the origin o is when it is at A & when it is at B, then a. b. The relationship between depends upon the slope of the line AB. c. d.

30. Problem 27 The particle executing simple harmonic motion has a kinetic energy . The maximum value of the potential energy & the total energy are respectively a. b. c. d.

31. Problem 28 Charge +q &-q are placed at point A& B respectively which are a distance 2L apart, C is the midpoint between A & B. the work done is moving a charge +Q along the semicircle CRD is a. b. c. d.

32. Problem 29 Monochromatic light of frequency is produced by a laser. The power emitted is . the number of photons emitted, on the average, by the source per second is a. b. c. d.

33. Problem 30 Three point charges +q,-2q & +q are placed at points ( x=0 , y=a, z=0) , ( x=0 , y=0, z=0) , ( x=a , y=0, z=0) respectively . The magnitude & the direction of the electric dipole moment vector of this charge assembly are qa along the line joining points ( x=0 , y=0, z=0) & ( x=a , y=a, z=0) qa along the line joining points ( x=0 , y=0, z=0) & ( x=a , y=a, z=0) qa along +x direction qa along +y direction

34. Problem 31 Two satellites of earth, are moving in the same orbit. The mass of is four times the mass of . Which one of the following statement is true? The potential energies of earth & satellite in the two case are equal are moving with same speed The kinetic energy of two energies are equal The time period of is four time of

35. Problem 32 are two vectors & is the angle between them, if , the value of is a. b. c. d.

36. Problem 33 A mass of 2.0kg is put on a flat pan attached to a vertical spring fixed on the ground as shown in the figure. The mass of the spring & the pan is negligible. When pressed slightly & released the mass executes a simple harmonic motion. The spring constant is 200 N/m .what should be the minimum amplitude of the motion so that the mass gets detached from the pan (take g=10 ). 10.0cm Any value less than 12.0cm 4.0cm 8.0cm

37. Problem 34 A Charged particle (charged q) is moving in a circle in of radius R with uniform speed v. The associated magnetic moment μ is given by qvR b. qvR/2. c. d.

38. Problem 35 The total energy of electron in the ground state of hydrogen atom is -13.6 eV. The kinetic energy of an electron in the first excited state is 6.8 eV 13.6 eV 1.7 eV 3.4 eV

39. Problem 36 A 5 watt source emits monochromatic light of wavelength . When placed 0.5m away, it liberates photoelectrons from a photosensitive metallic surface. When the source is moved to a distance of 1.0m, the number of photoelectrons liberated will be reduced by a factor of 8 16 2 4

40. Problem 37 A particle executes simple harmonic oscillation with an amplitude a. the period of oscillation is T. the minimum time taken by the particle to travel half of the amplitude from the equilibrium position is T/8 T/12 T/4 T/4

41. Problem 38 For a cubic crystal structure which one of the following relations indicating the cell characteristics is correct? a. b. c. d.

42. Problem 39 Two condenser one of capacity C & other of capacity C/2 are connected to a V- volt battery, as shown. The work done in charging fully both the condensers is a. b. c. d.

43. Problem 40 A black body is at . It emits energy at a rate which is proportional to a. b. c. d.

44. Problem 41 The resistance of an ammeter is 13 & its scale is graduated for a current up to 100 amps. After an additional shunt has been connected to this ammeter its become possible to measure currents up to 750 amperes by this meter. The value of shunt resistance is a. b. c. d.

45. Problem 42 If the vertices P, Q, R of a triangle PQR are rational points, which of the following points of the triangle PQR is (are) always rational points (s)? Centroid In centre Circumventer Orthocenter

46. Problem 43 An engine has an efficiency of 1/6. When the temperature of sink is reduced by , its efficiency is doubled. Temperature of source is a. b. c. d.

47. Problem 44 What is the value of the inductance L for which the current is maximum in a series LCR circuit with 1mH Cannot be calculated unless R is known 10mH 100mH

48. Problem 45 Nickel shows ferromagnetic property at room temperature. If temperature is increased beyond Curie temperature, then it will show Anti ferromagnetism No magnetic property Diamagnetism paramagnetic

49. Problem 46 A vertical spring with force constant k is fixed on a table. A ball of mass m at height h above the free upper end of the spring falls vertically on the spring so that the spring is compressed by a distance d. the net work done in the process is a. b. c. d.

50. Problem 47 Under the influence of a uniform magnetic field a charged particle is moving in a circle of a radius R with constant speed v. the time period of the motion Depend on both R & v Is in depend on both R & v Depend on R & not on v Depend on v & not on R

51. Problem 48 If the cold junction of a thermo- couple is kept at & the hot junction is kept at , then the relation between neutral temperature & temperature of inversion is a. b. c. d.

52. Problem 49 Assuming the sun to have a spherical outer surface of radius r, radiating like a black body at temperature , the power received by a unit surface ,( normal to the incident ray) at a distance R from the center of the sun is, ( is stefan’s constant) a. b. c. d.

53. Problem 50 In the energy band diagram of a material shown below, the open circles & filled circles denote holes & electron respectively. The material is An insulator A metal An n-type semiconductor An p-type semiconductor

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