1. aipmt–Past papers PHYSICS- UNSOLVED PAPER - 1996

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 minimum wavelength of the X-rays produced by electrons accelerated through a potential difference of V volts is directly proportion to a.1/v b. √v c. V2 d.1/√v

4. Problem 02 A beam of electrons is moving with constant velocity in a region having electric and magnetic fields of strength 20 Vm-1 and 0.5 T at right angles to the direction of motion of the electrons. What is the velocity of the electrons? 8 ms-1 5.5 ms-1 20 ms-1 40 ms-1

5. Problem 03 An electron beam has a kinetic energy equal to 100 eV. Find its wavelength associated with a beam, if mass of electron = 9.1 x 10-31 kg and 1 eV = 1.6 x 10-19 J/eV. (Planck’s constant = 6.6 x 10-34 J-s) 24. 6 Å 0.12 Å 1.2 Å 6.3 Å.

6. Problem 04 A man fires a bullet of mass 200 gm at speed of 5 m/s. the gun is of one kg mass. By what velocity the gun rebounds backward? 1 m/s 0.01m/s 0.1m/s 10 m/s.

7. Problem 05 In a Fresnel baptism experiment, the two positions of lens give separation between the slits as 16 cm and 9 cm respectively. What is the actual distance of separation? 13 cm 14 cm 12.5 cm 12 cm.

8. Problem 06 A 10 eV electron is circulating in a plane at right angles to a uniform field at magnetic induction 10-4Wb/m2 (= 1.0 gauss), the orbital radius of electron is 11 cm 18 cm 12 cm 16 cm.

9. Problem 07 A linear harmonic oscillator of force constant 2 x 106 N/m and amplitude 0.01 m has a total mechanical energy of 160 J. Its P.E. is 160 J P.E. is zero P.E. is 100 J P.E. is 120 J

10. Problem 08 When NPN transistor is used as an amplifier, then Electrons move from collector to base Holes move from base to emitter Electrons move from base to collector Electrons move from emitter to base.

11. Problem 09 When arsenic is added as an impurity to silicon, the resulting material is n-type conductor n-type semiconductor p-type semiconductor none of these.

12. Problem 10 When using a triode, as an amplifier, the electrons are emitted by Grid and collected by cathode only Cathode and collected by the anode only Anode and collected by cathode only Anode and collected by the gird and by cathode.

13. Problem 11 The energy of a hydrogen atom in its ground state is-13.6 eV. The energy of the level corresponding to the quantum number n = 2 in the hydrogen atom is -0.54 eV -3.4 eV -2.72 eV -0.85 eV.

14. Problem 12 According to Bohr’s principle, the relation between principal quantum number (n) and radius of orbit is a. b. c. d.

15. Problem 13 In a discharge tube at 0.02 mm, there is formation of Crooke’s dark space Faraday’s dark space Both space partly None of these

16. Problem 14 A metal ring is held horizontally and bar magnet is dropped through the ring with its length along the axis of the ring. The acceleration of the falling magnet is More than g Equal to g Less than g Either ‘a’ or ‘c’.

17. Problem 15 The magnetic field dB due to a small current element dl at a distance and element carrying current I is a. b. c. d.

18. Problem 16 The energy stored in a capacitor of capacity C and potential V is given by a.CV/2 b. C2V2/2 c. CV2/2 d. C2V/2

19. Problem 17 A point charge + q is placed at the mid-point of cube of side l. The electric flux emerging from the cube is a. b. c. zero d.

20. Problem 18 An electron of mass m and charge e is accelerated from rest through a potential difference V in vacuum. Its final velocity will be a. √2eV/m b. √eV/m c. 2V/2m d. eV/m

21. Problem 19 Light travels through a glass plate of thickness t and having a refractive index . If c is the velocity of light in vacuum, the time taken by light to travel this thickness of glass is a. t/μc b. μt/c c. Tμc d. tc/μ

22. Problem 20 The work done in turning a magnet of magnetic moment M by an angle of 900 from the meridian, is n times the corresponding work done to turn it through an angle of 600. The value of n is given by 1/2 1/4 2 1.

23. Problem 21 A ray of light from a denser medium strikes a rare medium as shown in figure. The reflected and refracted rays makes an angle of 900 with each other. The angles of refection and refraction are r and r’. The critical angle would be sin-1 (tan r) tan-1 (sin r) sin-1 (tan r) tan-1 (sin r)

24. Problem 22 At 0 K which of the following properties of a gas will be zero ? Vibration energy Density Kinetic energy Potential energy.

25. Problem 23 The refractive index of water is 1.33. What will be the speed of light in water ? 4 x 108 m/s 1.33 x 108 m/s 3 x 108 m/s 2.25 x 108 m/s

26. Problem 24 Two sound waves having a phase difference of 600 have path difference of a.λ/6 b. λ/3 c. 21 d. λ/2

27. Problem 25 A diatomic gas initially at 180C is compressed adiabatically to one eighth of its original volume. The temperature after compression will be 395.40C 1440C 180C 887.40C

28. Problem 26 An ideal gas, undergoing adiabatic change, has which of the following pressure temperature relationship? = constant = constant = constant = constant

29. Problem 27 A truth table is give. Which of the following has this type of truth table? AND gate OR gate XOR gate NOR gate

30. Problem 28 This symbol represents AND gate NOR gate NAND gate OR gate.

31. Problem 29 The value of critical temperature in terms of Van der Waals’ constant a and b is given by a. b. c. d.

32. Problem 30 Two vectors are such that . The angle between the two vectors will be 1800 00 600 900

33. Problem 31 A nucleus ruptures into two nuclear parts, which have their velocity ratio equal to 2 : 1. What will be the ratio of their nuclear size (nuclear radius)? 31/2 : 1 1 : 31/2 21/3 : 1 1 : 21/3

34. Problem 32 A moving body of mass m and velocity 3 km/hour collides with a rest body of mass 2m and sticks to it. Now the combined mass starts to move. What will be the combined velocity ? 3km/hour 4km/hour 1 km/hour 2 km/hour

35. Problem 33 The kinetic energy (Ek) of a photoelectron varies with the frequency (v) of the incident radiation as which of the following graph? a. b. c. d.

36. Problem 34 A ball is dropped from a spacecraft revolving around the earth at a height of 120 km. What will happen to the ball? It will fall down to the earth gradually It will go very far in the space It will continue to move with the same speed along the original orbit of spacecraft It will move with the same speed, tangentially to the spacecraft.

37. Problem 35 If a photon has velocity c and frequency v, then which of the following represents its wavelength? a. Hv/c2 b. hv c. hc/E d. hv/c

38. Problem 36 The dimensions of impulse are equal to that of Pressure Linear momentum Force Angular momentum.

39. Problem 37 The equation of a sound wave is y =0.0015 sin (62.4x + 316t). Find the wavelength of this wave 0.3 unit 0.2 unit 0.1unit cannot be calculated.

40. Problem 38 A force vector applied on a mass is represented as and accelerates with 1 m/s2. What will be the mass of the body? a.10 kg b.20 kg c.10√2kg d. 2√10kg

41. Problem 39 A body dropped from a height h with initial velocity zero, strikes the ground with a velocity 3 m/s. Another body of same mass dropped from the same height h with an initial velocity of 4 m/s. Find the final velocity of second mass, with which it strikes the ground 5m/s 12 m/s 3 m/s 4 m/s.

42. Problem 40 A particle starts with S.H.M. from the mean position as shown in the fig. Below. Its amplitude is A and its time period is T. At one time, its speed is half that of the maximum speed. What is this displacement? a.2A/√3 b. 3A/√2 c.√2A/3 d.√3A/2

43. Problem 41 What will be the formulae of mass of the earth in terms of g, R and G? a. b. c. d.

44. Problem 42 The velocity of photons is proportional to (where v = frequency) a.1/√v b. V2 c. v d. √v

45. Problem 43 If a convex lens of focal length 80 cm and a concave lens of focal length 50 cm are combined together, what will be their resulting power ? + 7.5 D -0.75 D + 6. 5 D -6.5 D.

46. Problem 44 The density of a cube is measured by meausuring its mass and length of its sides. If the maximum error in the measurement of mass and lengths are 3% and 2% respectively, the maximum error in the measurement of density would be 12% 14 % 7% 9 %.

47. Problem 45 An equation is given here where P = Pressure, V = Volume and = Absolute temperature. If a and b are constants, the dimensions of ‘a’ will be ML-5T-1 ML5T1 ML5T2 M-1L5T2.

48. Problem 46 Which of the following dimensions will be the same as that of time ? a. L/R b. C/L c.LC d. R/L

49. Problem 47 Two equal electric currents are flowing perpendicular to each other shown in the figure. AB and CD are perpendicular to each other and symmetrically placed with respect to the currents. Where do we expect the resultant magnetic field to be zero? On CD On AB On both OD and BO On both AB and CD.

50. Problem 48 A body is whirled in a horizontal circle of radius 20 cm. It has an angular velocity of 10 rad/s. What is its linear velocity at any point on circular path ? 20 m/s √2 m/s 10 m/s 2 m/s.

51. Problem 49 A 10 N force is applied on a body produce in it an acceleration of 1 m/s2. The mass of the body is 15 kg 20 kg 10 kg 5 kg.

52. Problem 50 What will be the equivalent resistance between the two points A and D? 30Ω 40 Ω 10 Ω 10 Ω

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