Magnetism Fundamentals1. What do you call the phenomenon whereby

substance attracts pieces of iron?A. PermeabilityB. MagnetismC. NaturalismD. Electromagnetism

2. The condition in which a substance attracts pieces of iron is known asA. ElectromagnetismB. ElectrolysisC. MagnetismD. Magnetic Induction

3. A substance that attracts pieces iron is known asA. magnetB. conductorC. ferriteD. superconductor

4. A natural magnetA. loadstoneB. carbonC. lodestoneD. magnesium

5. Group of magnetically aligned atoms.A. LatticeB. CrystalC. DomainD. Range

6. In a magnet, what do you call the point in which the magnetic lines of force is maximum?A. maximum poleB. intensified poleC. unit poleD. magnetic pole

7. Which of the following refers to a characteristic of a magnetic line of force?A. Travels from south to north through

the surrounding medium of a bar magnet

B. Travels back and forth between the north and south pole of a bar magnet

C. Travels from north to south through the surrounding medium of a bar magnet

D. Stay stationary between the north and the south of a bar magnet

8. Is believed to be the pole where the magnetic lines of force are originating.A. North PoleB. South PoleC. Unit PoleD. Universal Pole

9. What do you call a pole that when place in air with a similar and equal pole will cause a force of repulsion of 1/4πμο Newtons?A. South PoleB. Unit poleC. Convergence poleD. Universal Pole

10. In a magnet, the straight line passing through the two poles is calledA. real axisB. imaginary axisC. Cartesian axisD. magnetic axis

11. The phenomenon in which a substance becomes a magnet when placed near a magnet.A. magnetic transferB. magnetic inductionC. electromagnetismD. magnetism

12. A force which causes a substance to become a magnet.A. magnetizing forceB. magnetomotiveC. creative forceD. electromagnetic force

13. What do you call the quantity of magnetism retained by a magnetic material after the withdrawal of a magnetizing force?A. Left over magnetismB. CoercivityC. HysteresisD. Residual magnetism

14. Is the property of magnetic materials, which retain magnetism after the withdrawal of magnetizing force.A. retentivityB. permeabilityC. reluctivityD. susceptability

15. A substance having high retentivity is best suited in makingA. an electromagnetB. a temporary magnetC. a permanent magnetD. two pole magnet

16. Which of the materials below that can be easily magnetized?A. soft magnetic materialsB. hard magnetic materialsC. low conductive materialsD. high conductive materials

17. Materials that can be easily magnetized in both directionsA. soft magnetic materialsB. hard magnetic materialsC. diamagneticD. paramagnetic

18. Ability of a material to conduct magnetic flux through it refers toA. permittivityB. permeabilityC. reluctivityD. conductivity

19. The ability to concentrate magnetic lines of force.A. retentivityB. permeabilityC. susceptabilityD. reluctivity

20. The permeability of free space.A. 4π x 10-7 H/mB. 12.56 x 10-7 F/mC. 8.854 x 10-7 H/mD. 8.854 x 10-12 F/m

21. The ratio of material permeability to the permeability of air or vacuum.A. relative conductivityB. relative permeabilityC. inverse permeabilityD. inverse permittivity

22. What is the relative permeability of air?A. 0B. 1C. 4π x 10-7 H/mD. 8.854 x 10-12 F/m

23. Materials with permeability slightly less than that of free space.A. diamagneticB. paramagneticC. ferromagneticD. antimagnetic

24. Materials with permeability slightly greater than that of free space.A. diamagneticB. paramagneticC. ferromagneticD. antimagnetic

25. What do you call materials, which possess very high permeabilities?A. diamagneticB. paramagneticC. ferromagneticD. antimagnetic

26. What is the relative permeability of paramagnetic substance?A. slightly greater than 1B. very much greater than 1C. slightly less than 1D. very much smaller than 1

27. Permeability of a material means:A. The ability of the material to

conduct electric fieldB. The conductivity of the material for

electromagnetic fieldC. The ability of the material to hold

magnetic fluxD. The conductivity of the material for

magnetic lines of force

28. Nonmetallic materials that has ferromagnetic properties.A. termitesB. ferritesC. ferrousD. loadstone

29. Cores of magnetic equipment use magnetic material which hasA. very low permeabilityB. moderate permeabilityC. low permeabilityD. high permeability

30. Hydrogen is an example of a _________ material.A. diamagneticB. ferromagneticC. paramagneticD. magnetic

31. Cobalt is an example of a _________ material.A. diamagneticB. ferromagneticC. paramagneticD. magnetic

32. The space outside a magnet where its poles has a force of attraction or repulsion on another magnetic pole.A. magnetic fieldB. magnetic fluxC. magnetic flux densityD. magnetic lines of force

33. The imaginary lines representing the magnetic field.A. magnetic fieldB. magnetic fluxC. magnetic flux densityD. magnetic lines of force

34. What do you call the total number of magnetic lines of force in a magnetic field?A. magnetic fieldB. magnetic fluxC. magnetic flux densityD. magnetic lines of force

35. The number of lines per unit area in a plane perpendicular to the magnetic lines of force.A. magnetic fieldB. magnetic fluxC. magnetic flux densityD. magnetic lines of force

36. The direction of field lines outside a magnet isA. from north to south poleB. from south to north poleC. either from north to south or south

to north poleD. dependent on the magnet’s

orientation with respect to the earth’s magnetic pole

37. The entire group of magnetic field lines flowing outward from the north pole of a magnet.A. magnetic fieldB. magnetic flux densityC. magnetic fluxD. electromagnetic field

38. Magnetic lines of force are calledA. magnetic fieldB. magnetic flux density

C. magnetic fluxD. electromagnetic field

39. What is the unit of magnetic flux in SI system?A. WeberB. MaxwellC. TeslaD. Gauss

40. The unit of magnetic flux density in SI:A. GaussB. WeberC. MaxwellD. Tesla

41. A magnetic flux of 25,000 maxwell in an area of 5 sqcm. results in flux density ofA. 5,000 Gauss (G)B. 125,000 GC. 5,000 Tesla (T)D. 125,000 T

42. Calculate the flux density in Gauss (G) having a flux of 12,000 Mx through a perpendicular area of 6cm.A. 200 GB. 2,000 GC. 7,200 GD. 72,000 G

43. What does a gaussmeter measure?A. fluxB. magnetic fieldC. magnetic flux densityD. mmf

44. The capacity of a substance to become magnetized. This is expressed as a ratio between the magnetization produced in a substance to the magnetizing force producing it.A. magnetic conductivityB. magnetic susceptibilityC. magnetic resistivityD. magnetic reluctivity

45. The typical saturation flux density for most magnetic materials.A. 0.1 Wb/m2

B. 2 Wb/m2

C. 10 Wb/m2

D. 20 Wb/m2

46. The force between two magnetic poles is _________ permeability of the medium.A. directly proportional to theB. inversely proportional to the

C. not dependent of theD. exponentially proportional to the

47. If the distance between two magnetic poles is halve, the force between themA. decreases two timesB. decreases four timesC. increases two timesD. increases four times

48. A force of 20 N is acting on a 10 Wb magnetic pole, calculate the intensity of the magnetic field?A. 0.5 N/WbB. 2 N/WbC. 10 N/WbD. 20 N/Wb

49. Unit of permeabilityA. Henry/meter (H/m)B. Farad/meter (F/m)C. Henry-meter (H-m)D. Farad-meter (F-m)

50. The unit of permittivityA. Henry/meter (H/m)B. Farad/meter (F/m)C. Henry-meter (H-m)D. Farad-meter (F-m)

51. Magnetic intensity isA. a vector quantityB. a scalar quantityC. an imaginary quantityD. either a vector or scalar

52. The Gauss is a unit ofA. permeabilityB. electromagnetic forceC. magnetic forceD. magnetic flux density

53. What is the unit of flux in cgs?A. Ampere-turn (At)B. Coulomb/sec. (C/s)C. Maxwell (Mx)D. Gauss

54. One Weber is equivalent toA. 108 MaxwellsB. 106 MaxwellsC. 104 MaxwellsD. 102 Maxwells

55. The equivalent of 1 x 109 Maxwells isA. 1 WeberB. 10 WeberC. 100 WeberD. 1,000 Weber

56. A magnetic flux of 500,000,000 lines is equivalent toA. 5 x 108 MaxwellsB. 5 WeberC. 500 x 106 MAxwellsD. all of the above

57. The unit of flux density in mksA. GaussB. Weber/m2

C. MaxwellD. Tesla

58. What do you call the force that sets up or tends to set up magnetic flux in a magnetic circuit?A. electromotive forceB. potential differenceC. magnetomotive forceD. dynamic force

59. Voltage in electrical circuits is analogous to _________ in magnetic circuits.A. Ampere-turnB. Magnetomotive forceC. Magnetizing forceD. Flux

60. Electrical current is analogous to _________ in magnetic circuits.A. Ampere-turnB. Magnetomotive forceC. Magnetizing forceD. Flux

61. __________ capability is analogous to permeance.A. AdmittanceB. ConductanceC. ReluctanceD. Resistance

62. Resistance in electrical circuits is analogous to _________ in magnetic circuits.A. ConductanceB. PermeanceC. ElastanceD. reluctance

63. The property of a material which opposes the creation of magnetic flux.A. elastanceB. permeanceC. susceptanceD. reluctance

64. The reciprocal of reluctanceA. conductanceB. permeanceC. elastanceD. capacitance

65. Permeance is analogous toA. conductanceB. resistanceC. impedanceD. elastance

66. Is the reciprocal of reluctance and implies the readiness of a material to develop magnetic flux.A. elastanceB. permeanceC. susceptanceD. conductance

67. Magnetic circuit property that permits flux.A. elastanceB. permeanceC. susceptanceD. conductance

68. It is easier to establish flux line in soft iron than it is to establish them in air, this is because iron has a lowerA. PermeanceB. InductanceC. elastanceD. reluctance

69. The Oersted (Oe) is the same asA. 1 Gb/cmB. 1 Gb/mC. 10 Gb/cmD. 10 Gb/cm

70. The unit of reluctanceA. GilbertB. TeslaC. At/WbD. Gauss

71. It is the specific reluctance of a material.A. resistivityB. retentivityC. reluctivityD. permeability

72. At/m is a unit ofA. magnetic fieldB. reluctance

C. magnetizing forceD. magnetic power

73. Magnetomotive force has a unit ofA. Volt (V)B. Watt (W)C. Joule (J)D. Ampere-turn (At)

74. The cgs unit of magnetomotive forceA. VoltB. WeberC. GilbertD. Ampere-turn

75. One Gilbert is equal toA. 0.0796 AtB. 0.796 AtC. 7.96 AtD. 79.6 At

76. One Ampere-turn (At) is equivalent toA. 0.126 GilbertB. 1.260 GilbertsC. 12.60 GilbertsD. 126 Gilberts

77. The current needed for a coil of 200 turns to provide a 400 ampere turn magnetizing force isA. 2 AB. 4 AC. 6 AD. 8 A

78. Determine the ampere-turns when a 10 V battery is connected across a solenoid having 100 turns and a resistance of 5 Ω.A. 50 AtB. 200 AtC. 100 AtD. 1,000 At

79. What is residual magnetism?A. The external magnetic field when the

current is flowing through the exciting coil.

B. The flux density, which exist in the iron core when the magnetic field intensity is reduced to zero.

C. The flux density, which exist in the iron core when the magnetic field intensity is at its maximum value.

D. The flux density when the magnetic core is saturated.

80. When you demagnetize property by applying an AC field and then gradually reduced it to zero, it is called

A. dampingB. decayingC. degaussingD. gaussing

81. In a magnetic circuit, a flux that drifts away from its intended path is calledA. lost fluxB. linked fluxC. drift fluxD. leakage flux

82. Is the quantity of magnetizing force needed to counter balance the residual magnetism of a magnetic material.A. hysteresisB. degaussingC. retentivityD. coercivity

83. What do you call the loss of electrical energy in counter balancing the residual magnetism in each cycle?A. hysteresisB. magnetomotiveC. leakageD. coercivity

84. The amount of magnetic field needed to remove residual magnetism from a transformer core during each half cycle is called theA. coercive forceB. residual fieldC. hysteresis fieldD. demagnetizing force

85. If a wire coil has 100 turns and carries 1.3 A of current, calculate the magnetomotive force in Gilbert.A. 163.3B. 16.33C. 1.633D. 0.1633

86. An advantage of an electromagnet over a permanent magnetA. An electromagnet can be demagnetizedB. An electromagnet is simplerC. An electromagnet is cheaperD. An electromagnet can be switched ON

and OFF87. Electromagnet whose core is in the form

of a close magnetic ringA. solenoidB. relayC. toroidD. circular

88. Magnetic flux can always be attributed to

A. static charged particlesB. motion of charge particlesC. static electric fieldD. every applied potential

89. What is a magnetic field?A. A force set up when current flows

through a conductor.B. A force set up when a charged body

is at static.C. The space between two electrically

charged particles.D. The space around a conductor.

90. Which of the following determines the strength of a magnetic field around a conductor?A. amount of currentB. diameter of the conductorC. length of the conductorD. amount of voltage

91. The magnetic flux around a straight, current carrying wire, is strongerA. near the edgeB. near the wireC. at the centerD. at both edge

92. In what direction is the magnetic field about a conductor when current is flowing?A. In a direction determined by the

left-hand rule.B. Always in a clock wise direction.C. Always in a counter clockwise

direction.D. In a direction determined by the

right-hand screw rule.

93. If the electrical current carried by each of the two long parallel wire is doubled, and their separation is also doubled, the force between themA. also doublesB. increases by a factor of fourC. decreases by a factor of fourD. decreases by a factor of two

94. Reversing the flow of current in a circuitA. reverses the magnetic polarityB. increase the magnetic field

intensityC. decreases the magnetic intensityD. enhances hysteresis

95. Is used to maintain strength of magnetic field.

A. storerB. energizerC. gausserD. keeper

96. What law that describes the force of attraction or repulsion between two magnetic poles is directly proportional to their strengths?A. Coulomb’s first lawB. Coulomb’s second lawC. Ampere’s lawD. Gauss’ law

97. What is the law whereby the force of attraction or repulsion between poles is inversely proportional to the square of the distance between them?A. Coulomb’s first lawB. Coulomb’s second lawC. Coulomb’s third lawD. Coulomb’s law

98. The physical motion resulting from the forces of magnetic fields.A. motor actionB. linear motionC. rectilinear motionD. generator action

99. What law in electronics where an induced current will be in such a direction that its own magnetic field will oppose the magnetic field that produces the same?A. Electromagnetic lawB. Nortons lawC. Lenz lawD. Maxwell law

100. A changing magnetic fieldA. produces an electric fieldB. induces potentialC. produces a fluctuating electric

fieldD. produces a steady electric field

101. The emf induced in a coil due to the change of its flux linked with it is calledA. mutual emfB. crossfire induced emfC. self induced emfD. virtually induced emf

102. If two coils are close enough together for their magnetic fields to interact, a change in current in one will induce a corresponding voltage in the other, This condition is known

A. self-inductanceB. mutual inductanceC. crossfire inductanceD. linked inductance

103. If the magnetic flux through a coil changes, the induced EMF acts in such a direction as toA. oppose that changeB. magnify that changeC. augment that changeD. amplify that change

104. When a conductor is moved through a magnetic field a voltage is always induced. The amount of voltage is always proportional toA. the diameter of the conductor usedB. the length of the conductorC. the distance of the conductor from

the fieldD. the rate at which the conductor is

moved

105. The term of energy that is stored in an electromagnetic or electrostatic fieldA. kinetic energyB. static energyC. dynamic energyD. potential energy

106. What is meant by back EMF?A. A voltage that is applied in the

reverse direction.B. An EMF that is dude to the fly wheel

effect.C. An EMF that is generated from the

back of an electromagnet.D. A voltage that opposes the applied

EMF.

107. When current in a conductor increases, Lenz’ law states that the self-induced potential willA. produce current opposite to the

increasing currentB. tend to produce more magnetic fieldC. tend to augment the increase in

currentD. produce current with the same

direction to the increasing current

108. If a magnetic flux occurs across 100 turns at a rate of 2 Wb/sec. What is the induced voltage as per Faraday’s law?A. 100 VB. 400 VC. 200 V

D. 800 V

109. The circuit element that is used represent the energy stored in a magnetic field.A. resistanceB. capacitanceC. inductanceD. elastance

110. Which of the given below can produce the most induced voltage?A. 1 A dcB. 1 A, 60 HzC. 50 A dcD. 1 A, 400 Hz

111. In all cases of electromagnetic induction, the current set-up by an induced voltage tends to create flux whose direction opposes any change in the existing flux. This law is calledA. Ampere’s lawB. Lenz’ lawC. Coulomb’s lawD. Faraday’s law

112. In electromagnetism, what law that determines the polarity of an induced voltage?A. Ampere’s lawB. Lenz’ lawC. Coulomb’s lawD. Faraday’s law

113. In electromagnetism, what law that determines the amount of induced voltage?A. Ampere’s lawB. Lenz’ lawC. Coulomb’s lawD. Faraday’s law

114. Electromotive force (emf) is induced whenever a conductor cuts magnetic fluxA. Faraday’s first lawB. Faraday’s second lawC. Coulomb’s first lawD. Coulomb’s second law

115. The magnitude of electromotive force (emf) that is induced when a conductor cuts magnetic flux is directly proportional to its rate.A. Faraday’s first lawB. Faraday’s second lawC. Coulomb’s first lawD. Coulomb’s second law

116. The effect that describes the ability of a mechanically stressed ferromagnetic wire to recognize rapid switching of magnetization when subjected to a DC magnetic field.A. Wiegand effectB. Wertheim effectC. Wiedemann effectD. Wall effect

117. The concept whereby a small voltage is generated by a conductor with current in an external magnetic field is known asA. Wiegand effectB. Hall effectC. Wiedemann effectD. Wall effect

118. _________ is called the magnetic field.A. The force that drives current

through a resistorB. Current flow through space around a

permanent magnetC. The force between the plates of

charged capacitorD. A force set up when current flow

through a conductor119. The natural magnet refers to

A. steelB. soft ironC. magnesiaD. loadstone (lodestone)

120. The force between two magnetic poles in relation to their pole strength is ________.A. not relatedB. inversely proportionalC. directly proportionalD. independent