1. To obtain an n-type semiconductor germanium crystal it must be doped with foreign atoms whose valency is

2. To obtain a p-type semi-conductor Si Crystal must be doped with foreign atoms whose valency is

3. The operation of a transistor requires

4. In forward bias the width of potential barrier

5. The working of transistor as amplifier is similar to

6. The electronic circuits which implement the various logic operations are called

7. An OP-AMP comparator is a circuit that compares the signal voltage on one of its inputs with a _

8. An OP-AMPs can amplify

9. Non-inverting amplifier circuits have

10. In nucleus of uranium the number of neutrons will be

11. During fusion of hydrogen into helium

12. One amu is equal to

13. According to which one of following law the density of atom is uniform?

14. For chain reaction to build up the size of the radioactive target should be

15. Antimatter consists of

16. Neutron and proton are commonly known as

17. Half life of radium is 1590 years. In how many years shall the earth loss all its radium due to radioactive decay?

18. Which one of the following radiation possesses maximum penetrating power?

19. Electrons

20. Radioactivity is a ______ (A) Spontaneous activity (B) Chemical property

21. Energy liberated when one atom of U-235 undergoes fission reaction is

22. Transuranic elements have atomic number

23. Nuclear forces exist between

24. Mass defect per nucleon is

25. Tick the correct statement

26. The bombardment of nitrogen with ?-particles will produce

27. Diameter of an atom is approximately

28. Radioactive decay obeys which one of the following law?

29. Average energy required to remove one nucleon from the nucleus is called

30. Fission chain reaction in a nuclear reactor can be controlled by introducing

31. Which one of the following radiations possesses maximum velocity?

32. Charge on an electron was determine by

33. Charge on neutron is

34. A particle having the mass of an electron and the charge of a proton is called a

35. Mass of neutron is

36. Nuclei having the same mass number but different atomic number are

37. A mass spectrograph (spectrometer) sorts out

38. Sum of the masses of constituent nucleons as compared to the mass of the resultant nucleus is

39. An ?-particle is emitted from 88Ra226. What is the mass and atomic number of the daughter nucleus?

40. The unit of radioactivity curie is equal to

41. During fission process a large amount of

42. In liquid metal fast breeder reactor the type of uranium used is

43. Radioactive materials can be identified by measuring their

44. If one or more of the neutrons emitted during fission cab be used to build up further fission then the reaction is self sustained and is known as

45. Pair production takes place in the vicinity of a heavy nucleus so that

46. During an encounter with an atom ?-particle knocks out

47. The path of ?-particle is

48. Which of the following radiations are suitable for the treatment of an infection in the interior of the body ?

49. Various types of cancer are treated by

50. Sterilization of surgical instruments medical supplies and bandages can be done by exposing them to a beam of