DCE (Delhi College of Engineering) Entrance Examination Sample Paper - Physics

1. Following two wave trains are approaching each other.
y₁ = a sin 200 p t      y₂ = a sin 208 p t
The number of beats heard per second is :

2. One of the geo-stationary satellites of India is vertically above

3. Light of wavelength 2400 x 10^-10 m in air will become light of wavelength in glass (m = 1.5) equal to

4. The ratio of secondary to primary turns is 4:5. If power input is P, what will be the ratio of power output (neglect all losses) to power input ?

5. Lenz's law applies to

6. If a proton and anti-proton come close to each other and annihilate, how much energy will be released ?

7. If Sn is doped with As, what will be the result ?

8. A charge is placed at the centre of a cube, what is the electric flux passing through one of its faces?

9. What is the degree of freedom in case of a mono atomic gas ?

11. Speed of recession of galaxy is proportional to its distance

12. If a substance goes in a magnetic field and is pushed out of it, what is it ?

13. Which is not a scalar quantity?

14. Minimum energy required to excite an electron in a Hydrogen atom in ground state is :

15. If Gravitational Constant is decreasing in time, what will remain unchanged in case of a satellite orbiting around earth ?

16. If a transparent medium of refractive index m = 1.5 and thickness t = 2.5 x 10^-5 m is inserted in front of one of the slits of Young's Double Slit experiment, how much will be the shift in the interference pattern ? The distance between the slits is 5.0 x 10^-3 cm and that between slits and screen is 100 cm.

17. How does light propagate in optical fibres?

18. Dispersion of light is due to

19. Which of the following conclusions is correct regarding a stationary body?

20. Energy released in stars is due to

21. 13 days is the half-life period of a sample. After how many days, the sample will become 1/16th of the original substance ?

22. Absolute zero is the temperature at which

23. Motion of liquid in a tube is described by

24. Molecular motion shows itself as

25. Which is this gate ?

26. Energy bands in solids are a consequence of

27. A boy of mass M stands on the floor of an elevator moving downwards with an acceleration a which is less than g. The force exerted by the boy on the floor of the elevator is

28. A body A of mass m₁ exerts a force on another body B of mass m₂. If the acceleration of B be a₂, then the acceleration (in magnitude ) of A is

29. What does not change when sound enters from one medium to another ?

30. Resolving power of a microscope depends upon

31. An astronaut of weight Mg is in a rocket accelerating upward with an acceleration of 4g. The apparent weight of the astronaut will be

32. One proton beam enters a magnetic field of 10^-4 m/s normally, sp. charge = 10¹¹ C/kg, velocity = 10⁹ m/s. What is the radius of the circle describe by it ?

33. If a black body radiates 20 calories per second at 227°C, it will radiate at 727°C

34. If a carnot engine is working with source temperature equal to 227°C and its sink temperature is at 27°C, its efficiency will be

35. If the frequency of an oscillating particle is n, then the frequency of oscillation of its potential energy is

36. If an electron oscillates at a frequency of 1 GHz, it gives :

37. Earth's atmosphere is richest in

38. Cathode rays consist of

39. A body of mass m₁ is moving with a velocity V. It collides with another stationary body of mass m₂. They get embedded. At the point of collision, the velocity of the system

40. One projectile moving with velocity V in space, gets burst into 2 parts of masses in the ratio 1:2. The smaller part becomes stationary. What is the velocity of the other part ?

41. A thief steals a box of weight W & jumps from the third floor of a building. During jump, he experiences a weight of

42. Two electron beams are moving parallel in space but in opposite directions; then

43. Two wires with resistances R and 3R are connected in parallel, the ratio of heat generated in 2R and R is

44. A wire is drawn such that its radius changes from r to 2r, the new resistance is

45. In solids, inter-atomic forces are

46. When horse starts running all of a sudden, the rider on the horse back falls backward because

47. What should be the minimum velocity at the highest point of a body tied to a string, so that the string just does not slack ?

48. If a person standing on a rotating disc stretches out his hands, the speed will:

49. EMF is most closely related to

50. Planetary system in the solar system describes

51. Lenz's law is based upon

52. Faraday's second law states that mass deposited on the electrode is directly proportional to

53. Unit of power is

54. Power can be expressed as

55. Units of coefficient of viscosity are

56. Dimensions of torque are

57. A body of weight mg is hanging on a string, which extends its length by l. The work done in extending the string is

58. The water droplets in free fall are spherical due to

59. A ball of mass 1Kg is accelerating at a rate of 1ms^-2. The rate of change of momentum is

60. A body orbitting around earth at a mean radius which is two times as great as the parking orbit of a satellite. The period of the body is

61. Gamma rays are