X PHYSICS
UNIT – XI
ELECTRONICS
1. At absolute zero (OK) conduction band is completely ____________.
2. Rubber is an ____________.
3. A ____________ is a periodic array of atoms in three dimensions.
4. The upper energy band which is vacant is called ____________.
5. Energy gap is also called ____________.
6. The valence band and conduction band overlap in ____________.
7. Metals are ____________ of electricity.
8. The energy gap of a semiconductor is about ____________.
9. ____________ is a positive charge carrier of current.
10. Semi conductors are classified into two types. They are ____________ and ____________.
11. In a crystal, atoms are not five but one ____________ together.
12. Crystal is formed by brining a large number of ____________ together.
13. A group of closely spaced energy levels is called ____________.
14. A group of energy levels is broadly called ____________.
15. Insulators are ____________ conductors of electricity.
16. Substances that conduct electricity are known a____________.
17. In a conductor valence and ____________ bands overlap.
18. The absence of an electron in valence band is a ____________.
19. The number of free electrons are more in ____________.
20. The charge carriers in a semi-conductor are ____________.
21. Pure semiconductors are called ____________ semi-conductors.
22. In n-type semiconductor the majority carriers are ____________.
23. The concentration of free electrons is more in ____________.
24. An intrinsic semi-conductor at 0oK behaves as an ____________.
25. The electron and hole currents are equal in an ____________ semiconductor. 26. ____________ semi conductors are the semiconductors doped with desired impurity. 27. Trivalent impurities are called ____________.
28. A p type semiconductor is a semi conductor containing ____________ impurity atoms. 29. Silicon atom can form ____________ covalent bonds.
30. Phosphorus is a ____________ impurity.
31. p-types and n-types semi conductors are electrically ____________.
32. In pure germanium the gap is ____________.
33. Intrinsic semi conductors are the semi conductors without ____________.
34. Pentavalent impurities are called ____________.
35. A semiconductor acts as an insulator at ____________.
36. The charge carriers in semi conductors are ____________.
37. Under ____________ bias condition a diode conducts.
38. Majority carriers of charge in n-type are ____________.
39. In ____________ condition diode does not conduct current.
40. ____________ is used as rectifier.
41. A p-n junction diode offers a ___________ under reverse bias condition.
42. Diodes are used in ____________ circuits.
43. The three terminals of a transistor are called ____________.
44. Transistor acts as an ____________.
45. A p-n diode consists of only one ____________ junction.
46. A ____________ is a combination of two diodes joined back to back.
47. The junction transistor is the main component in an ____________ circuit.
48. Chips are important in the ____________.
49. In a full wave rectifier the minimum number of diodes needed is ____________.
50. r.f. stands for ____________.
51. The process of fixing messages to r.f carrier waves is called ____________.
52. The ____________ circuits selects the desired modulated signals.
53. FM is the abbreviation for ____________.
54. Modulated waves are sent into space by a ____________.
55. ____________ is the process of extracting information from the modulated r.f. carrier waves.
56. Nowadays ____________ is used for scanning purpose.
57. Messages are converted into ____________ signals.
58. Transmitted modulate r.f. wave carries ____________.
59. Demodulation is the process of extracting information from the modulated ____________ carrier wave.
60. Tuning circuits are known as ____________.
X PHYSICS
UNIT – XI
ELECTRONICS ( Key )
(1) empty (2) insulator (3) crystal (4) Conduction band (5) forbidden gap (6) conductors (7) good conductors (8) 1 ev (9) hole (10) intrinsic, extrinsic semiconductors (11) bound (12) atoms (13) energy band (14) energy levels (15) poor (16) electric conductors (17) conduction (18) hole (19) copper (20) electrons and holes (21) intrinsic (22) electrons (23) copper (24) insulator (25) intrinsic (26) Extrinsic (27) acceptors (28) trivalent (29) 4 (30) Pentavalent. (31) neutral (32) 0.72 ev (33) impurities (34) donors (35) 0°K (36) electrons and holes (37) forward (38) electrons (39) reverse bias (40) Diode (41) high resistance (42) rectifier (43) emitter, base, collector (44) amplifier (45) flow (46) transistor (47) amplifier (48) micro electronic systems (49) two (50) Radio Frequency (51) modulation (52) Tuning (53) frequency modulation (54) transmitting antenna (55) Demodulation (56) Iconoscope (57) electrical (58) messages (59) r.f (60) detectors.
