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Multiple Choice Questions 1. Which of the following is true for electrostatics? a. πΈ = ββπ b. β 2V = 0 c. Both (a) and (b) d. None of these 2. According to Coulomb's Law, force between two point charges is a. β (distance)2 b. β (distance) c. (a) and (b) d. None 3. The value of Ξ΅ 0 the absolute permittivity is ________ pF/m. a. 8.854 b. 8.854 × 10β12 c. 8.845 × 10β10 d. 8.854 × 10β10 4. Electric field intensity is related to force F and charge q as __________. a. E=F/Q b. E=Q/F c. E=FQ d. E=F.Q 5. Electric field intensity due to volume charge is given as a. πΈ = ββπ π b. πΈ = 4πβπ 2 P c. πΈ = β« ππ£ππ£ 4πβπ β« ππ ππ d. πΈ = 4πβπ 6. Electric flux density________medium. a. Depends on b. Independent of c. Both (a) and (b) d. None of these 7. Poisson's equation is given as a. πΈ = ββ2 π ππ£ b. β2 π = β β c. β2 π=0 d. All 8. Electric potential V is given as π a. π = 4πβπ b. V=ββE c. Both (a) and (b) d. None Page 1 of 12 9. Potential energy of a test charge, when moved from a lower potential point to a higher potential point. a. Remains the same b. Increases c. Decreases d. Becomes zero 10. As per Gauss's Law, the total electric flux Ο through a closed surface and the total charge q enc by that surface are related as a. β = β« π΅ππ b. Q=β c. Both d. None 11. Identify the configuration in figure 1 that is not a correct representation of I and H. (a) fig. a (b) fig. b (c) fig. c (d) both fig. d and e 12. In equation B = ππΏπ¨ , vector magnetic potential is (a) B (b) A (c) Both (d) None 13. A charge of 12 C has velocity of 5ax + 2ay - 3az m/s. Determine F on the charge in the field of (a) E=18ax,+5ay +10az V/m (b) B = 4ax + 4ay + 3az wb/m2. (a) F = 254.27 N and 415.17 N (b) 154.17N and 315.17 N ( c) Both are possible (d) Nil 14. A rectangular coil is placed in a field of B = (2ax + ay) wb/m2. The coil is in y-z plane and has d(a) Scalar quantity (b) Vector quantity (c) Both (d) None imensions of 2 m x 2 m. It carries a current of 1 A. Find the torque about the z-axis. (a) 6ay (b) (b) 6 az N-m (c) (c) 4 az (d) (d) 4 Az N-m Page 2 of 12 15. Inductance of a toroid and solenoid are given respectively by (a) πΏ = πππ 2 2ππ πππ 2 (b) πΏ = π (c) Either (d) None and πΏ = and πΏ = πππ 2 π πππ 2 2ππ 16. Electric charge, electric potential, energy, temperature etc. are examples of a) Scalar quantity (b) Vector quantity (c) Both (d) None 17. Force, Electric field intensity are the examples of (a) 18. Scalar quantity (b) Vector quantity (c) Both (d) None represents (a) Scalar or dot product (b) Vector or Cross product (c) Both (d) None 19. Coulombβs law gives (a) Force between two charges (b)Energy between two charges (c) both (d) None 20. Force per unit charge is (a) Electric field intensity (b) Electric potential (c) both (d) None (b) None 21. Capacitance is (a) Charge per unit area (b) Charge per volts (c) Charge/ length (d) None 22. Lorentz force equation comprises __________ and __________ forces. a. b. c. d. Electric, magnetic Mechanical, chemical Both (a) and (b) None of these 23. Magnetic flux density is a relation of a. b. c. d. Current and area Area and its direction Magnetic flux and area None of these Page 3 of 12 24. Magnetic flux density is analogous to a. Magnetic induction b. Electric field strength c. Both (a) and (b) d. Electric flux density 25. Total flux passing through a closed surface held in a magnetic field is a. Infinity b. Zero c. Unity d. None of these 26. Magnetic vector potential for volume current is expressed as a. π΅ = β × π΄ b. π΄ = β × π΅ c. π΅ = β. π΄ d. π΄ = β. π΅ 27. -----Can be obtained from vector magnetic potential . a. Magnetic field intensity b. Magnetic flux density c. Both (a) and (b) d. None of these 28. According to right hand thumb rule, thumb indicates a. Flow of current b. Non-uniform magnetic field c. Both (a) and (b) d. Magnetic field lines 29. Energy density W H is given as __________. a. Energy per volume b. Energy per area c. Linear enenrgy d. All of these 30. When two charges of +2C and -0.5C are brought in contact and then separated the charges on each charge will be a. Equal and same b. Unequal and same c. Equal and opposite d. Unequal and opposite 31. Magnitude of dipole moment is given as a. qd b. q/d c. d/q d. None of these 32. If work done W mn is zero, then V N and V M are related as a. VN + VM = 0 b. V N β V M = 0 c. 2V N + V M = 0 d. V N + 2V M = 0 Page 4 of 12 33. Charge distribution symmetry can be of . a. Spherical type b. Cylindrical type c. Planar type d. All of these 34. Curl of electrostatic field is a. β b. 1 c. 0 d. None of these 35. As per Stoke's Theorem, H the magnetic field intensity is a. β b. 1 c. 0 d. None of these 36. In the case of a linear material medium, which equation can be derived easily from Gauss' law. a. Poisson b. Laplace c. Both (a) and (b) d. None of these 37. According to ampereβs law a. Total electric flux is equal to electric charge b. Total magnetic flux is equal to electric charge c. Total magnetic flux is equal to current passing d. None of these 38. Electric and magnetic fields are a. Perpendicular to each other b. Parallel to each other c. Both (a) and (b) d. None of these 39. Angular velocity has units of a. Radians b. Meter c. Radians/meter d. None of these πππππ΄ 40. Capacitance of parallel plate capacitor is given by π where Ξ΅ o represents a) b) c) d) Permittivity (b) Area (c) Absolute permittivity (d) None Page 5 of 12 41. Energy stored in a capacitor is given by 1 (a) W=2 πΆπ 2 (b) W=Q2/2C (c) Both (d) None. 42. F=qBXV represents the force exerted on a (a) Charge q moving with velocity V in an electric field (b) Charge q moving with velocity V in a magnetic field B (c) Both (d) None 43. When there is change in magnetic flux, emf is induced. This statement is a. b. c. d. Faraday's First Faraday's Second Faraday's Third Faraday's Fourth 44. The direction of emf induced is always such as to oppose the very reason producing the emf. This is according to a. b. c. d. BioβSavart's Lenz's Ampere's Faraday's 45. BiotβSavart's Law is expressed mathematically as a. π» b. π΅ β β« πΌπππ πππ/π 2 c. β« π»ππ = πΌπππ d. β« π»ππ = β«(βXH)ds 46. BiotβSavart's Law can be applied to current-carrying conductors of a. Large length b. Medium length c. Small length d. Very small length Page 6 of 12 47. The magnitude of the emf induced is directly proportional to rate of change of flux. This is put forth by a. BioβSavart's b. Faradayβs I law c. Ampere's d. Faradayβs II law 48. According to Ampere's Circuital Law, field intensity at a point at distance R from a very long straight filament conductor-carrying current I is given as a. β« π»ππ = πΌπππ b. β« π½ππ = πΌ c. Both (a) and (b) d. None 49. Ampere's Circuital Law and which of the following law in electrostatics are analogous a. Lenz's b. Gauss's c. BiotβSavart's d. Faraday's 50. Ampere's Circuital Law can be applied __________ the conductor. a. Inside b. Outside c. Both (a) and (b) d. None of these 51. In the above expression, r represents (a) Distance between charge and point (b) Distance between current element and the point under consideration (c) Distance between two charges (d) None 52. According to Maxwell's first equation in integral form a. b. c. d. β. π· = ππ£ β« π·ππ = β«(β. D)dv β« π»ππ = β«(βXH)ds βXH = Jc + Jd 52. According to Maxwell's first equation in differential form gives a. b. c. d. β. π· = ππ£ β« π·ππ = β«(β. D)dv β« π»ππ = β«(βXH)ds βXH = Jc + Jd Page 7 of 12 53. According to Maxwell's second equation in differential form gives a. β. π· = ππ£ b. β« π·ππ = β«(β. D)dv c. β« π»ππ = β«(βXH)ds d. βXH = Jc + Jd 54. According to Maxwell's second equation in integral form gives a. β. π· = ππ£ b. β« π·ππ = β«(β. D)dv c. β« π»ππ = β«(βXH)ds d. βXH = Jc + Jd 55. Maxwell's third equation in differential form gives a. β. π· = ππ£ b. β« πΈππ = β«(βXE)ds c. β« π»ππ = β«(βXH)ds d. βXE = β βB/ βt 56. Maxwell's third equation in integal form gives a. β. π· = ππ£ b. β« πΈππ = β«(βXE)ds c. β« π»ππ = β«(βXH)ds d. βXE = β βB/ βt 57. Maxwell's fourth equation in differential form gives a. β. π΅ = 0 b. β« π΅ππ = 0 c. β« π»ππ = β«(βXH)ds d. βXE = β βB/ βt 58. Maxwell's fourth equation in integral form gives a. β. π΅ = 0 b. β« π΅ππ = 0 c. β« π»ππ = β«(βXH)ds d. βXE = β βB/ βt 59. Maxwell's equations involve a. Charge density b. Current density c. Magnetic intensity d. All of these 60. Maxwell's equations are based on __________ law(s). a. Faraday's b. Gauss's c. Ampere's d. All of these Page 8 of 12 61. Maxwell's equations in __________ form give information at points of discontinuity in electromagnetic fields. a. Differential b. Integral c. Algebraic d. None of these 62. According to Ampere's Circuital Law a. β« π»ππ = πΌ b. β« π»ππ = πΌπππ c. β« π»ππ = β«(βXH)ds d. βXE = β βB/ βt 63. Steady magnetic fields are governed by a. BiotβSavart's law b. Ampere's Circuital law c. Both (a) and (b) d. None of these 64. Wave speed in terms of frequency f and wavelength Ξ» is expressed as. a. f/Ξ» b. Ξ»/f c. Ξ» f d. (Ξ» + f) 65. For a lossy dielectric medium, a. Ο = 0 b. Ο β 0 c. None of these d. Cannot say 66. In the case of a perfect dielectric medium conductivity of wave is a. More than 100% b. Approaches 100% c. Less than 100% d. None of these 67. Phase velocity is given as a. π = ππ b. Ξ²/Ο c. both (a) and (b) d. None of these 68. For a good conductor a. ππ β₯ π b. ππ β€ π c. ππ == π d. None 69. For a good dielectric medium a. ππ β₯ π b. ππ β€ π c. ππ == π d. None Page 9 of 12 70. In good conductors, rate of attenuation is a. Small b. Large c. Infinity d. Zero 71. Poynting Vector is obtained as a. π = πΈ × π» b. π = πΈ × π» c. πΈ = π × π» d. π» = πΈ × π 72. Power density is a. Power delivered b. Power /area c. Both (a) and (b) d. None of these 73. Reflection coefficient Ξ is a. β₯100 b. = 10 c. β€ 1 d. None of these 74. As referred to the waves, correct equation is a. (1 + Ξ) = Ο b. (1 + Ο) = Ξ c. (1 + Ξ) Ο = 0 d. (1 + Ο)Ξ = 0 75. Standing wave consists of two travelling waves of ____________ amplitudes and _____________ is direction. a. Unequal, same b. Unequal, opposite c. Equal, same d. Equal, opposite 76. Standing wave ratio is given as 1+π a. πππ = 1βπ 1βπ b. πππ = 1+π c. None d. Both 77. SWR ranges from ______. a. 0 to 1 b. 1 to 10 c. 10 to 100 d. 1 to β Page 10 of 12 78. Waves are used in __________. a. TV b. Radio c. Radar d. All of these 79. Curl of magnetic field intensity is (a) Current density (b) Magnetic field intensity Page 11 of 12 (c) Current (d) None Answers for the Multiple Choice Questions 1. (c) 2. (d) 3. (b) 4. (a) 5. (c) 6. (a) 7. (b) 8. (c) 9. (b) 10. (c) 11. (c) 12. (a) 13. (a) 14. (d) 15. (a) 16. (a) 17. (b) 18. (a) 19. (a) 20. (a) 21. (b) 22. (A) 23. (c) 24. (d) 25. (b) 26. (a) 27. (c) 28. (d) 29. (a) 30. (a) 31. (a) 32. (a) 33. (d) 34. (c) 35. (c) 36. (c) 37. (c) 38. (a) 39. (d) 40. (c) 41. (c) 42. (b) 43. (a) 44. (b) 45. (b) 46. (a) 47. (d) 48. (a) 49. (b) 50. (b) 51. (b) 52. (b) 53. (a) 54. (d) 55. (c) 56. (d) 57. (b) 58. (a) 59. (b) 60. (d) Page 12 of 12 61. (d) 62. (a) 63. (b) 64. (c) 65. (c) 66. (b) 67. (b) 68. (a) 69. (b) 70. (a) 71. (b) 72. (b) 73. (b) 74. (c) 75. (b) 76. (d) 77. (a) 78. (a) 79. (d) 80. (a)