This document contains 28 physics problems from an unsolved IITJEE past paper from 2004. The problems cover topics including kinematics, optics, electricity, magnetism, thermodynamics, and properties of gases. For each problem, multiple choice options for the answer are provided. The document states that the solutions can be found by visiting a specific website.

1. IITJEE –Past papers PHYSICS -UNSOLVED PAPER - 2004

2. SECTION – I Single Correct Answer Type Select the correct choice amongst the given alternative answers.

3. 01 Problem The energy E of a photon is equal to the kinetic energy of a helium particle. If is the de Broglie wavelength of the helium particle and is the wavelength of the photon ,the ratio is proportional to a. Eo b. E1/2 c. E-1 d. E-2

4. Problem 02 While discharging an RC circuit, the variation of In with time is shown by the dotted line in the figure, If the resistance is halved, the variation of In versus time is best represented by the curve P Q R S

5. Problem 03 White light is incident on the interface of glass and air as shown in the figure. If green light is just totally internally reflected, the emerging light contains yellow,orange,red violet,indigo,blue all colors all colors except green

6. Problem 04 In the expression ,P is pressure is distance is Boltzmann constant and θ is the temperature. The dimensional formula of βwill be a. b. c. d.

7. Problem 05 Six equal resistances are connected between points A,B and C as shown in the figure. The net resistance will be maximum between A and B B and C A and C any two points

8. Problem 06 A ray of light is incident on an equilateral glass prism placed on a horizontal table(shown in the figure).For minimum deviation, which of the following is correct? PQ is horizontal QR is a horizontal RS is horizontal Either PQ or RS is horizontal

9. Problem 07 A particle at the organ is under the influence of a force (where k is a positive constant).If the potential energy U is zero at x=0,the variation of potential energy with the coordinate x is represented as a. b. c. d.

10. 08 Problem A small block slides without friction down an inclined plane starting from the rest.If is the distance travelled from time is a. b. c. d.

11. Problem 09 Three balck bodies A,B and C having diameters 2 m,4 m and 6 m,respectively,emit radiation of maximum intensity at 300nm,400nm and 500 nm, respectively .The power radiated by them are respectively.Which of the folowing facts regarding powers is correct? is maximum is maximum is maximum d.

12. Problem 10 A closed organ pipe of length L and an open organ pipe contain gases of densities ,respectively. The compressibility of gases are equal in both the pipes. Both the pipes are vibrating in their second overtone with same frequency. The length of the open organ pipe is a. b. c. d.

13. Problem 11 A block A of mass m is placed on a frictionless horizontal surface. Another block B of same mass is kept on A and connected to the wall with the help of a spring of spring constant k as shown in the figure. The coefficient of friction between A and B is .The blocks move together performing simple harmonic motion of amplitude A. The maximum value of the friction force between A and B is a. b. c. zero d.

14. 12 Problem An ideal gas expands isothermally from a volume and then compressed to original volume V1 adiabatically. Initial pressure is P1 and final pressure is P3.The total work done is W .Then a. b. c. d.

15. Problem 13 Figure shows the variation of photocurrent with anode potential for a photo-secnsitive surface for a photo-secsitive surface for three different radiations. Let be the intensities and be the frequencies for the curves a,b and c,respectively.Which of the following facts is correct ? a. b. c. d.

16. Problem 14 A particle starts from rest. Its acceleration (a) with time(t0 is shown in the figure. The maximum speed of the particle will be 20 m/s 60 m/s 550 m/s 660 m/s

17. Problem 15 Six charge, three positive and three negative of equal magnitude, are to be placed at the vertices of a regular hexagon ,shown in the figure such that the electric field at the centre O is double the electric field when only one positive charge of same magnitude is placed at R.Which of the following arrangements of charges is possible for P,Q,R,S,t and Irrespectively. +,-,+,-,-,+ +,-,+,-,+,- +,+,-,+,-,- -,+,+,-,+,-

18. Problem 16 After 420 days, the activity of a radioactive sample is 6000 dps. The activity reduces to 3000 dps after another 140 days. The initial activity of the sample in dps is 6000 12000 24000 48000

19. 17 Problem Light from a sodium lamp when passed though a prism has a minimum angle of deviation of .The index of refraction of the prism is 1.125 1.200 1.372 1.414

20. Problem 18 Liquid oxygen at 50K is heated to 300 K at constant pressure of 1 atm.The rate of heating is constant .Which of the following graphs represents the variation of temperature with time? a. b. c. d.

21. Problem 19 Two identical conducting rods are first connected independently to two vessels, one containing water at 100 and the other containing ice at o .In the second case, the rods are joined end to end and connected to the same vessels. Let be the rate of melting of ice in the two cases, respectively. The ratio is 1/2 2/1 4/1 1/4

22. Problem 20 A disc is rolling (without slipping) on a horizontal surface, shown in the figure. C is its centre and A and B are two points equidistant from C. Let be the magnitudes of velocities of A,B and C, respectively, then a. b. c. d.

23. Problem 21 A source of sound of frequency 600 Hz is placed inside water. The speed of sound in water is 1500 m/s and air it is 300 m/s .The frequency of sound recorded by an observer who is standing in air is 12 Hz 200 Hz 600 Hz 3000 Hz

24. Problem 22 A point object is placed at the centre of a glass sphere of radius 8 cm and refractive index 1.5.The distance of the virtual image from the surface of the sphere is 2 cm 4 cm 8 cm 12 cm

25. Problem 23 For the post office box arrangement,shown in the figure to determine the value of unknown resistance, the unknown resistance should be connected between B and C C and D A and D d.

26. Problem 24 A child is standing with folded hands at the centre of a platform rotating about its central axis. The kinetic energy of the system is K. The child stretches his arms so that the moment of inerta of the system triples .The kinetic energy of the system now is K K/3 K/4 4k

27. Problem 25 An electron moving with a speed u along the positive x-axis. At y=0,it enters a region of uniform magnetic field which exists from the region after some time with the speed v at coordinate y, then a. b. c. d.

28. Problem 26 In a Young’s double slit experiment, bichromatic light of wavelengths 400 nm and 560 nm are used. The distance between the slits is 0.1 mm and the distance between the slits and screen is 1 m. The minimum distance between two minima is 4 mm 5.6 mm 14 mm 28 mm

29. Problem 27 The variation of induced elf with time in a coil if a short bar magnet is moved along its axis ,(shown in the figure),with a constant velocity is best represented as a. b. c. d.

30. Problem 28 Which of the following statements regarding mean free path of gaseous molecules is correct? Directly proportional to the number of molecules per unit volume Directly proportional to the average speed of molecules Inversely proportional to the square of molecular diameter Inversely proportional to the temperature of the gas

31. FOR SOLUTION VISIT WWW.VASISTA.NET