(CATALYST GROUP) B"sic Electric"l Engineering

Transcription

1 (CATALYST GROUP) B"sic Electric"l Engineering 1. Kirchhoff s current l"w st"tes th"t (") net current flow "t the junction is positive (b) Hebr"ic sum of the currents meeting "t the junction is zero (c) no current c"n le"ve the junction without some current entering it. (d) tot"l sum of currents meeting "t the junction is zero 2. According to Kirchhoffs volt"ge l"w, the "lgebr"ic sum of "ll IR drops "nd e.m.fs. in "ny closed loop of " network is "lw"ys (") neg"tive (b) positive (c) determined by b"ttery e.m.fs. (d) zero 3. Kirchhoffs current l"w is "pplic"ble to only (") junction in " network (b) closed loops in " network (c) electric circuits (d) electronic circuits 4. Kirchhoffs volt"ge l"w is rel"ted to (") junction currents (b) b"ttery e.m.fs. (c) IR drops (d) both (b) "nd (c) (e) none of the "bove 5. Superposition theorem c"n be "pplied only to circuits h"ving (") resistive elements

2 (b) p"ssive elements (c) non-line"r elements (d) line"r bil"ter"l elements 6. The concept on which Superposition theorem is b"sed is (") reciprocity (b) du"lity (c) non-line"rity (d) line"rity 7. Thevenin resist"nce Rth is found (") by removing volt"ge sources "long with their intern"l resist"nces (6) by short-circuiting the given two termin"ls (c) between "ny two openʼ termin"ls (d) between s"me open termin"ls "s for Etk 8. An ide"l volt"ge source should h"ve (") l"rge v"lue of e.m.f. (b) sm"ll v"lue of e.m.f. (c) zero source resist"nce (d) infinite source resist"nce 9. For " volt"ge source (") termin"l volt"ge is "lw"ys lower th"n source e.m.f. (b) termin"l volt"ge c"nnot be higher th"n source e.m.f. (c) the source e.m.f. "nd termin"l volt"ge "re equ"l 10. To determine the pol"rity of the volt"ge drop "cross " resistor, it is necess"ry to know (") v"lue of current through the resistor (b) direction of current through the resistor

3 (c) v"lue of resistor (d) e.m.fs. in the circuit 11. M"ximum power output is obt"ined from " network when the lo"d resist"nce is equ"l to the output resist"nce of the network "s seen from the termin"ls of the lo"d. The "bove st"tement is "ssoci"ted with (") Millm"nʼs theorem (b) Theveninʼs theorem (c) Superposition theorem (d) M"ximum power tr"nsfer theorem 12. Any number of current sources in p"r"llel m"y be repl"ced by " single current source whose current is the "lgebr"ic sum of individu"l source currents "nd source resist"nce is the p"r"llel combin"tion of individu"l source resist"nces. The "bove st"tement is "ssoci"ted with (") Theveninʼs theorem (b) Millm"nʼs theorem (c) M"ximum power tr"nsfer theorem (d) None of the "bove 13. In "ny line"r bil"ter"l network, if " source of e.m.f. E in "ny br"nch produces " current I in "ny other br"nch, then s"me e.m.f. "cting in the second br"nch would produce the s"me current / in the first br"nch. The "bove st"tement is "ssoci"ted with (") compens"tion theorem (b) superposition theorem (c) reciprocity theorem

4 14. Which of the following is non-line"r circuit p"r"meter? (") Induct"nce (b) Condenser (c) Wire wound resistor (d) Tr"nsistor 15. A c"p"citor is gener"lly " (") bil"ter"l "nd "ctive component (b) "ctive, p"ssive, line"r "nd nonline"r component (c) line"r "nd bil"ter"l component (d) non-line"r "nd "ctive component 16. In "ny network cont"ining more th"n one sources of e.m.f. the current in "ny br"nch is the "lgebr"ic sum of " number of individu"l fictitious currents (the number being equ"l to the number of sources of e.m.f.), e"ch of which is due to sep"r"te "ction of e"ch source of e.m.f., t"ken in order, when the rem"ining sources of e.m.f. "re repl"ced by conductors, the resist"nces of which "re equ"l to the intern"l resist"nces of the respective sources. The "bove st"tement is "ssoci"ted with (") Theveninʼs theorem (b) Nortonʼs theorem (c) Superposition theorem (d) None of the "bove 17. Kirchhoff s l"w is "pplic"ble to (") p"ssive networks only (b) ".c. circuits only

5 (c) d.c. circuits only (d) both ".c. "s well d.c. circuits 18. Kirchhoff s l"w is not "pplic"ble to circuits with (") lumped p"r"meters (b) p"ssive elements (c) distributed p"r"meters (d) non-line"r resist"nces 19. Kirchhoff s volt"ge l"w "pplies to circuits with (") nonline"r elements only (b) line"r elements only (c) line"r, non-line"r, "ctive "nd p"ssive elements (d) line"r, non-line"r, "ctive, p"ssive, time v"rying "s wells "s time-inv"ri"nt elements 20. The resist"nce LM will be (") 6.66 Q (b) 12 Q (c) 18Q (d) 20Q 21. For high efficiency of tr"nsfer of power, intern"l resist"nce of the source should be (") equ"l to the lo"d resist"nce (b) less th"n the lo"d resist"nce (c) more th"n the lo"d resist"nce 22. Efficiency of power tr"nsfer when m"ximum tr"nsfer of power c xerosis

6 (") 100% (b) 80% (c) 75% (d) 50% 23. If resist"nce "cross LM in Fig is 15 ohms, the v"lue of R is (") 10 Q (6) 20 Q (c) 30 Q (d) 40 Q 24. For m"ximum tr"nsfer of power, intern"l resist"nce of the source should be (") equ"l to lo"d resist"nce (b) less th"n the lo"d resist"nce (c) gre"ter th"n the lo"d resist"nce 25. If the energy is supplied from " source, whose resist"nce is 1 ohm, to " lo"d of 100 ohms the source will be (") " volt"ge source (b) " current source (c) both of "bove 26. The circuit whose properties "re s"me in either direction is known "s (") unil"ter"l circuit (b) bil"ter"l circuit (c) irreversible circuit (d) reversible circuit

7 27. In " series p"r"llel circuit, "ny two resist"nces in the s"me current p"th must be in (") series with e"ch other (b) p"r"llel with e"ch other (c) series with the volt"ge source.ʼ (d) p"r"llel with the volt"ge source 28. The circuit h"s resistors, c"p"citors "nd semi-conductor diodes. The circuit will be known "s (") non-line"r circuit (b) line"r circuit (c) bil"ter"l circuit 29. A non-line"r network does not s"tisfy (") superposition condition (b) homogeneity condition (c) both homogeneity "s well "s superposition condition (d) homogeneity, superposition "nd "ssoci"tive condition 30. An ide"l volt"ge source h"s (") zero intern"l resist"nce (b) open circuit volt"ge equ"l to the volt"ge on full lo"d (c) termin"l volt"ge in proportion to current (d) termin"l volt"ge in proportion to lo"d 31. A network which cont"ins one or more th"n one source of e.m.f. is known "s (") line"r network (b) non-line"r network

8 (c) p"ssive network (d) "ctive network 32. The superposition theorem is "pplic"ble to (") line"r, non-line"r "nd time v"ri"nt responses (b) line"r "nd non-line"r resistors only (c) line"r responses only 33. Which of the following is not " nonline"r element? (") G"s diode (b) He"ter coil (c) Tunnel diode (d) Electric "rc Ans: 34. Applic"tion of Nortonʼs theorem to " circuit yields (") equiv"lent current source "nd imped"nce in series (6) equiv"lent current source "nd imped"nce in p"r"llel (c) equiv"lent imped"nce (d) equiv"lent current source 35. Millm"nʼs theorem yields (") equiv"lent resist"nce (6) equiv"lent imped"nce (c) equiv"lent volt"ge source (d) equiv"lent volt"ge or current source 36. The superposition theorem is "pplic"ble to (") volt"ge only (b) current only (c) both current "nd volt"ge

9 (d) current volt"ge "nd power 37. Between the br"nch volt"ges of " loop the Kirchhoff s volt"ge l"w imposes (") non-line"r constr"ints (b) line"r constr"ints (c) no constr"ints 38. A p"ssive network is one which cont"ins (") only v"ri"ble resist"nces (b) only some sources of e.m.f. in it (c) only two sources of e.m.f. in it (d) no source of e.m.f. in it 39. A termin"l where three on more br"nches meet is known "s (") node (b) terminus (c) combin"tion (d) "node 40. Which of the following is the p"ssive element? (") C"p"cit"nce (b) Ide"l current source (c) Ide"l volt"ge source (d) All of the "bove 41. Which of the following is " bil"ter"l element? (") Const"nt current source (b) Const"nt volt"ge source (c) C"p"cit"nce

10 (d) None of the "bove 42. A closed p"th m"de by sever"l br"nches of the network is known "s (") br"nch (b) loop (c) circuit (d) junction 43. A line"r resistor h"ving 0 < R < o is " (") current controlled resistor (6) volt"ge controlled resistor (c) both current controlled "nd volt"ge controlled resistor 44. A st"r circuit h"s element of resist"nce R/2. The equiv"lent delt" elements will be (") R/6 (b) fi? (c) 2R (d) 4R 45. A delt" circuit h"s e"ch element of v"lue R/2. The equiv"lent elements of st"r circuit with be (") RIG (b) R/3 (c) 2R (d) 3R 56. In Theveninʼs theorem, to find Z (") "ll independent current sources "re short circuited "nd independent

11 volt"ge sources "re open circuited (b) "ll independent volt"ge sources "re open circuited "nd "ll independent current sources "re short circuited (c) "ll independent volt"ge "nd current sources "re short circuited (d) "ll independent volt"ge sources "re short circuited "nd "ll independent current sources "re open circuited 57. While c"lcul"ting Rth in Theveninʼs theorem "nd Norton equiv"lent (") "ll independent sources "re m"de de"d (b) only current sources "re m"de de"d (c) only volt"ge sources "re m"de de"d (d) "ll volt"ge "nd current sources "re m"de de"d 58. The number of independent equ"tions to solve " network is equ"l to (") the number of chords (b) the number of br"nches (c) sum of the number of br"nches "nd chords (d) sum of number of br"nches, chords "nd nodes 59. The superposition theorem requires "s m"ny circuits to be solved "s there "re (") sources, nodes "nd meshes (b) sources "nd nodes (c) sources (d) nodes 60. Choose the incorrect st"tement. (") A br"nch formed by the p"r"llel connection of "ny resistor R "nd open circuit h"s the ch"r"cteristic of "n open circuit. (b) A br"nch formed by the p"r"llel connection of "ny resistor R "nd "

12 short circuit h"s the ch"r"cteristic of " short circuit. (c) A br"nch formed by the series connection of "ny resistor R "nd "n open circuit h"s the ch"r"cteristic of "n open circuit. (d) A br"nch formed by the series connection of "ny resistor R "nd " short circuit h"s the ch"r"cteristic of resistor R.