EEC 125 CBT Practice
const questions = [
{
question:"1. Magnetism is the property of a material by which it can:",
options:["Produce heat","Attract magnetic materials","Generate electricity","Emit light"],
answer:1
},
{
question:"2. Which of the following is NOT a magnetic material?",
options:["Iron","Nickel","Copper","Cobalt"],
answer:2
},
{
question:"3. The SI unit of magnetic flux is:",
options:["Tesla","Weber","Henry","Ampere"],
answer:1
},
{
question:"4. The symbol for magnetic flux is:",
options:["B","H","Φ","μ"],
answer:2
},
{
question:"5. Magnetic flux density is represented by:",
options:["Φ","μ","B","F"],
answer:2
},
{
question:"6. The SI unit of magnetic flux density is:",
options:["Tesla","Weber","Ampere-turn","Henry"],
answer:0
},
{
question:"7. Magnetic flux density is calculated as:",
options:["Φ × A","Φ / A","A / Φ","B × A"],
answer:1
},
{
question:"8. Magnetomotive force (MMF) is measured in:",
options:["Ampere","Tesla","Ampere-turn","Weber"],
answer:2
},
{
question:"9. The formula for magnetomotive force is:",
options:["B=Φ/A","F=IN","H=F/l","μ=B/H"],
answer:1
},
{
question:"10. Magnetic field strength is represented by:",
options:["B","H","μ","Φ"],
answer:1
}
];
{
question:"11. The SI unit of magnetic field strength is:",
options:["Tesla","A/m","Weber","Henry"],
answer:1
},
{
question:"12. Magnetic field strength is calculated using:",
options:["H = IN/l","B = Φ/A","F = ΦS","μ = B/H"],
answer:0
},
{
question:"13. Reluctance is the opposition to the flow of:",
options:["Current","Voltage","Magnetic flux","Power"],
answer:2
},
{
question:"14. The SI unit of reluctance is:",
options:["AT/Wb","Tesla","Henry","A/m"],
answer:0
},
{
question:"15. The formula for reluctance is:",
options:["S = F/Φ","B = Φ/A","F = IN","μ = B/H"],
answer:0
},
{
question:"16. Permeability is the ability of a material to:",
options:["Conduct electricity","Store charge","Allow magnetic flux to pass through it","Produce heat"],
answer:2
},
{
question:"17. The symbol for permeability is:",
options:["Φ","μ","B","H"],
answer:1
},
{
question:"18. The permeability of free space is represented by:",
options:["μr","μ0","B","Φ"],
answer:1
},
{
question:"19. The value of the permeability of free space is:",
options:["2π × 10⁻⁷ H/m","4π × 10⁻⁷ H/m","8π × 10⁻⁷ H/m","π × 10⁻⁷ H/m"],
answer:1
},
{
question:"20. Relative permeability is:",
options:["μ0/μ","μ/μ0","B/H","Φ/A"],
answer:1
},
{
question:"21. The symbol for magnetic flux density is:",
options:["Φ","B","H","μ"],
answer:1
},
{
question:"22. The relationship between magnetic flux density and magnetic flux is:",
options:["B = Φ × A","B = Φ/A","B = A/Φ","B = H/μ"],
answer:1
},
{
question:"23. Which of the following produces magnetomotive force?",
options:["Current flowing through a coil","Voltage only","Resistance","Capacitance"],
answer:0
},
{
question:"24. The magnetic equivalent of electric current is:",
options:["Voltage","Magnetic flux","Resistance","Power"],
answer:1
},
{
question:"25. The magnetic equivalent of electromotive force (e.m.f.) is:",
options:["Reluctance","Magnetomotive force","Flux density","Permeability"],
answer:1
},
{
question:"26. The magnetic equivalent of electrical resistance is:",
options:["Permeability","Reluctance","Flux","Current"],
answer:1
},
{
question:"27. The magnetic equivalent of electrical conductance is:",
options:["Permeance","Reluctance","Resistance","Magnetic field strength"],
answer:0
},
{
question:"28. In a magnetic circuit, the flow of magnetic flux is caused by:",
options:["Reluctance","Magnetomotive force","Resistance","Capacitance"],
answer:1
},
{
question:"29. Which law is the magnetic equivalent of Ohm's law?",
options:["Kirchhoff's Law","Hopkinson's Law","Faraday's Law","Lenz's Law"],
answer:1
},
{
question:"30. Hopkinson's Law is expressed as:",
options:["Φ = F/S","F = Φ × S","B = Φ/A","Both A and B"],
answer:3
},
{
question:"31. A magnetic circuit is a closed path followed by:",
options:["Electric current","Magnetic flux","Voltage","Electrons"],
answer:1
},
{
question:"32. An air gap in a magnetic circuit:",
options:["Reduces reluctance","Increases reluctance","Has no effect","Increases permeability"],
answer:1
},
{
question:"33. The purpose of an air gap in an electrical machine is to:",
options:["Increase magnetic flux","Control the magnetic field","Reduce voltage","Increase current"],
answer:1
},
{
question:"34. Which material has the lowest reluctance?",
options:["Air","Copper","Soft iron","Wood"],
answer:2
},
{
question:"35. The total reluctance of magnetic circuits connected in series is:",
options:["S₁ × S₂","S₁ + S₂","S₁/S₂","S₁ − S₂"],
answer:1
},
{
question:"36. If the magnetomotive force is doubled while reluctance remains constant, the magnetic flux will:",
options:["Remain the same","Be halved","Double","Become zero"],
answer:2
},
{
question:"37. Which expression is correct for magnetic flux?",
options:["Φ = F/S","Φ = S/F","Φ = B × H","Φ = μ × H"],
answer:0
},
{
question:"38. Increasing the number of turns in a coil will:",
options:["Decrease MMF","Increase MMF","Have no effect","Reduce magnetic flux"],
answer:1
},
{
question:"39. If current through a coil increases, the magnetomotive force will:",
options:["Decrease","Increase","Remain constant","Become zero"],
answer:1
},
{
question:"40. The SI unit of magnetic flux density is:",
options:["Weber","Tesla","Henry","Ampere-turn"],
answer:1
},
{
question:"41. Soft magnetic materials are mainly used for:",
options:["Permanent magnets","Transformer cores","Jewellery","Heating elements"],
answer:1
},
{
question:"42. Hard magnetic materials are mainly used for:",
options:["Transformer cores","Electromagnets","Permanent magnets","Relay cores"],
answer:2
},
{
question:"43. Which of the following is a soft magnetic material?",
options:["Soft iron","Steel","Alnico","Cobalt steel"],
answer:0
},
{
question:"44. Which of the following is a hard magnetic material?",
options:["Soft iron","Silicon steel","Cast steel","Pure iron"],
answer:2
},
{
question:"45. A good soft magnetic material should have:",
options:["High coercivity","High hysteresis loss","High permeability and low hysteresis loss","Low permeability"],
answer:2
},
{
question:"46. A good hard magnetic material should have:",
options:["Low retentivity","Low coercivity","High retentivity and high coercivity","High permeability only"],
answer:2
},
{
question:"47. The B-H curve shows the relationship between:",
options:["Current and voltage","Magnetic flux density and magnetic field strength","Resistance and current","Power and voltage"],
answer:1
},
{
question:"48. The area enclosed by a hysteresis loop represents:",
options:["Magnetic energy loss","Magnetic flux","Permeability","Reluctance"],
answer:0
},
{
question:"49. Hysteresis loss occurs due to:",
options:["Repeated magnetization and demagnetization","High voltage","Low resistance","High current only"],
answer:0
},
{
question:"50. Which of the following reduces hysteresis loss in magnetic cores?",
options:["Using hard steel","Using soft magnetic materials","Increasing air gap","Increasing resistance"],
answer:1
},
{
question:"51. Which of the following materials is commonly used for transformer cores?",
options:["Copper","Soft iron","Aluminium","Brass"],
answer:1
},
{
question:"52. Silicon steel is widely used because it has:",
options:["High hysteresis loss","Low permeability","Low hysteresis loss","High resistance only"],
answer:2
},
{
question:"53. The ability of a material to retain magnetism after the magnetizing force is removed is called:",
options:["Reluctance","Retentivity","Permeability","Conductivity"],
answer:1
},
{
question:"54. The property of a magnetic material that resists demagnetization is known as:",
options:["Permeability","Coercivity","Reluctance","Flux density"],
answer:1
},
{
question:"55. Which material has high retentivity?",
options:["Soft iron","Silicon steel","Hard steel","Ferrite core"],
answer:2
},
{
question:"56. Magnetic flux is directly proportional to:",
options:["Magnetomotive force","Reluctance","Resistance","Temperature"],
answer:0
},
{
question:"57. Increasing reluctance in a magnetic circuit will:",
options:["Increase flux","Decrease flux","Have no effect on flux","Double the flux"],
answer:1
},
{
question:"58. The magnetic equivalent of voltage in an electrical circuit is:",
options:["Flux","Current","Magnetomotive force","Permeability"],
answer:2
},
{
question:"59. The magnetic equivalent of electric current is:",
options:["Resistance","Flux","Voltage","Power"],
answer:1
},
{
question:"60. Which of the following is the magnetic equivalent of electrical resistance?",
options:["Permeability","Reluctance","Flux density","Magnetic field strength"],
answer:1
},
{
question:"61. The unit of relative permeability is:",
options:["Henry","Tesla","No unit","Weber"],
answer:2
},
{
question:"62. Relative permeability is the ratio of:",
options:["B/H","μ/μ₀","Φ/A","F/Φ"],
answer:1
},
{
question:"63. If the cross-sectional area of a magnetic path increases while flux remains constant, the flux density will:",
options:["Increase","Decrease","Remain constant","Become zero"],
answer:1
},
{
question:"64. Which of the following quantities is measured in Weber?",
options:["Magnetic field strength","Magnetic flux","Magnetic flux density","Reluctance"],
answer:1
},
{
question:"65. Which formula is used to calculate magnetic field strength?",
options:["H = F/l","B = Φ/A","F = IN","μ = B/H"],
answer:0
},
{
question:"66. Which of the following increases magnetomotive force?",
options:["Reducing current","Reducing the number of turns","Increasing current or number of turns","Increasing reluctance"],
answer:2
},
{
question:"67. The magnetic path in a transformer core is usually made as:",
options:["An open path","A closed path","A broken path","A curved wire"],
answer:1
},
{
question:"68. Which statement about magnetic flux is correct?",
options:["It flows only in copper","It always flows in a closed magnetic path","It exists only in air","It has the unit Ampere"],
answer:1
},
{
question:"69. A material with high permeability allows magnetic flux to:",
options:["Flow easily","Stop completely","Become electric current","Disappear"],
answer:0
},
{
question:"70. The relationship between magnetic flux, MMF, and reluctance is given by:",
options:["Φ = F/S","F = Φ × S","Both A and B","B = Φ/A"],
answer:2
},
{
question:"71. An air gap in a magnetic circuit mainly:",
options:["Increases permeability","Increases reluctance","Decreases reluctance","Has no effect"],
answer:1
},
{
question:"72. The total reluctance of a magnetic circuit with an air gap is:",
options:["Less than the core reluctance","Equal to the core reluctance","Greater than the core reluctance","Always zero"],
answer:2
},
{
question:"73. Which quantity is analogous to electric current in a magnetic circuit?",
options:["Voltage","Magnetic flux","Resistance","Power"],
answer:1
},
{
question:"74. Which quantity is analogous to voltage in a magnetic circuit?",
options:["Magnetomotive force","Flux density","Permeability","Reluctance"],
answer:0
},
{
question:"75. Which quantity is analogous to electrical resistance?",
options:["Permeability","Magnetic field strength","Reluctance","Flux"],
answer:2
},
{
question:"76. The magnetic equivalent of Ohm's law is:",
options:["F = Φ × S","Φ = F/S","Both A and B","H = F/l"],
answer:2
},
{
question:"77. The graph that shows the relationship between magnetic flux density and magnetic field strength is called:",
options:["V-I curve","B-H curve","P-I curve","I-R curve"],
answer:1
},
{
question:"78. The point at which a magnetic material cannot carry any more magnetic flux is called:",
options:["Retentivity","Coercivity","Magnetic saturation","Permeability"],
answer:2
},
{
question:"79. The area inside the hysteresis loop represents:",
options:["Resistance","Energy loss","Voltage drop","Current gain"],
answer:1
},
{
question:"80. Hysteresis loss can be reduced by using:",
options:["Hard steel","Soft magnetic materials","Copper","Air-core materials"],
answer:1
},
{
question:"91. The SI unit of magnetomotive force (MMF) is:",
options:["Ampere-turn (AT)","Tesla","Weber","Henry"],
answer:0
},
{
question:"92. Which equation correctly relates permeability, flux density and field strength?",
options:["μ = B/H","μ = H/B","B = μ/Φ","H = Φ/B"],
answer:0
},
{
question:"93. A magnetic material with low hysteresis loss is best suited for:",
options:["Permanent magnets","Transformer cores","Loudspeaker magnets","Compass needles"],
answer:1
},
{
question:"94. Which of the following is NOT an example of a soft magnetic material?",
options:["Soft iron","Silicon steel","Cast steel","Pure iron"],
answer:2
},
{
question:"95. Which of the following is an example of a hard magnetic material?",
options:["Soft iron","Silicon steel","Alnico","Ferrite core"],
answer:2
},
{
question:"96. When magnetic saturation occurs, further increase in magnetic field strength causes:",
options:["A large increase in flux density","No significant increase in flux density","A decrease in flux density","Flux density becomes zero"],
answer:1
},
{
question:"97. The magnetic field around a current-carrying conductor was first discovered by:",
options:["Faraday","Ampere","Oersted","Lenz"],
answer:2
},
{
question:"98. Which law states that the direction of the induced e.m.f. opposes the change causing it?",
options:["Faraday's Law","Ohm's Law","Lenz's Law","Hopkinson's Law"],
answer:2
},
{
question:"99. The magnetic circuit equivalent of electrical conductance is:",
options:["Reluctance","Permeance","Flux density","Permeability"],
answer:1
},
{
question:"100. Which statement is correct about a magnetic circuit?",
options:[
"Magnetic flux flows in a closed path",
"Magnetic flux is measured in amperes",
"Reluctance increases magnetic flux",
"Magnetic flux exists only in iron"
],
answer:0
},
{
question:"101. The symbol for magnetic field strength is:",
options:["B","H","Φ","μ"],
answer:1
},
{
question:"102. The magnetic constant is also known as:",
options:["Relative permeability","Permeability of free space","Flux density","Magnetic reluctance"],
answer:1
},
{
question:"103. Which of the following has the highest relative permeability?",
options:["Air","Vacuum","Soft iron","Wood"],
answer:2
},
{
question:"104. The unit of magnetic flux density is:",
options:["Tesla","Weber","Henry","Ampere-turn"],
answer:0
},
{
question:"105. If the cross-sectional area of a magnetic circuit decreases while flux remains constant, the flux density will:",
options:["Decrease","Increase","Remain the same","Become zero"],
answer:1
},
{
question:"106. Which magnetic material is commonly used in relay cores?",
options:["Soft iron","Cast steel","Alnico","Cobalt steel"],
answer:0
},
{
question:"107. The ability of a magnetic material to become easily magnetized is due to its:",
options:["High reluctance","High permeability","Low conductivity","High resistance"],
answer:1
},
{
question:"108. Which of the following is a non-magnetic material?",
options:["Iron","Nickel","Copper","Cobalt"],
answer:2
},
{
question:"109. The main purpose of laminating transformer cores is to reduce:",
options:["Hysteresis loss","Copper loss","Eddy current loss","Mechanical loss"],
answer:2
},
{
question:"110. Which magnetic property determines the ease with which magnetic flux passes through a material?",
options:["Retentivity","Permeability","Coercivity","Reluctance"],
answer:1
},
{
question:"111. Which magnetic quantity is measured in Ampere-turn (AT)?",
options:["Magnetic flux","Magnetomotive force","Flux density","Reluctance"],
answer:1
},
{
question:"112. If the current through a coil is 5 A and the number of turns is 200, the MMF is:",
options:["40 AT","200 AT","1000 AT","4000 AT"],
answer:2
},
{
question:"113. A magnetic circuit has an MMF of 500 AT and a reluctance of 100 AT/Wb. The magnetic flux is:",
options:["2 Wb","5 Wb","10 Wb","50 Wb"],
answer:1
},
{
question:"114. Which formula is used to calculate magnetic flux density?",
options:["B = Φ/A","B = H/μ","B = A/Φ","B = IN"],
answer:0
},
{
question:"115. Increasing the length of a magnetic path will:",
options:["Increase reluctance","Decrease reluctance","Increase permeability","Reduce MMF"],
answer:0
},
{
question:"116. Which of the following has the lowest permeability?",
options:["Soft iron","Silicon steel","Air","Nickel"],
answer:2
},
{
question:"117. The B-H curve is mainly used to study:",
options:["Electrical resistance","Magnetic properties of materials","Voltage regulation","Power factor"],
answer:1
},
{
question:"118. The horizontal axis of the B-H curve represents:",
options:["Magnetic flux density (B)","Magnetic field strength (H)","Magnetic flux (Φ)","Reluctance (S)"],
answer:1
},
{
question:"119. The vertical axis of the B-H curve represents:",
options:["Magnetic field strength (H)","Magnetic flux density (B)","Magnetomotive force (F)","Reluctance (S)"],
answer:1
},
{
question:"120. The area enclosed by the B-H hysteresis loop is proportional to:",
options:["Magnetic permeability","Magnetic energy loss","Flux density","Magnetic field strength"],
answer:1
},
{
{
question:"121. Hysteresis loss is represented by the:",
options:["Area under the B-H curve","Area inside the hysteresis loop","Slope of the B-H curve","Length of the magnetic path"],
answer:1
},
{
question:"122. Which of the following is NOT a property of a good soft magnetic material?",
options:["High permeability","Low coercivity","Low hysteresis loss","High retentivity"],
answer:3
},
{
question:"123. A permanent magnet should possess:",
options:["Low coercivity","High coercivity","Low retentivity","Low permeability"],
answer:1
},
{
question:"124. Which of the following materials is most suitable for making an electromagnet?",
options:["Soft iron","Cast iron","Alnico","Hardened steel"],
answer:0
},
{
question:"125. The magnetic equivalent of electric current is:",
options:["Magnetic flux","Magnetomotive force","Reluctance","Permeability"],
answer:0
},
{
question:"126. Which of the following quantities opposes the flow of magnetic flux?",
options:["Flux density","Permeability","Reluctance","Field strength"],
answer:2
},
{
question:"127. The relationship between magnetic flux density and magnetic field strength is:",
options:["B = μH","B = H/μ","H = Bμ","μ = HB"],
answer:0
},
{
question:"128. A magnetic circuit with high permeability will have:",
options:["High reluctance","Low reluctance","No magnetic flux","Infinite reluctance"],
answer:1
},
{
question:"129. The unit of magnetic field strength is:",
options:["Tesla","Ampere per metre (A/m)","Weber","Henry"],
answer:1
},
{
question:"130. The permeability of free space (μ₀) is approximately:",
options:["2π × 10⁻⁷ H/m","3π × 10⁻⁷ H/m","4π × 10⁻⁷ H/m","5π × 10⁻⁷ H/m"],
answer:2
},
{
question:"131. Which of the following is the SI unit of magnetic flux?",
options:["Tesla","Weber","Henry","Ampere"],
answer:1
},
{
question:"132. The symbol for relative permeability is:",
options:["μ","μ₀","μr","Φ"],
answer:2
},
{
question:"133. Relative permeability is always:",
options:["Greater than or equal to zero","Negative","Measured in Henry","Measured in Tesla"],
answer:0
},
{
question:"134. Which of the following magnetic materials is used in transformer cores?",
options:["Alnico","Soft iron","Hardened steel","Cast iron"],
answer:1
},
{
question:"135. The magnetic field around a straight current-carrying conductor is in the form of:",
options:["Straight lines","Concentric circles","Ellipses","Parabolas"],
answer:1
},
{
question:"136. Which rule is used to determine the direction of the magnetic field around a current-carrying conductor?",
options:["Fleming's Left-hand Rule","Fleming's Right-hand Rule","Right-hand Grip Rule","Lenz's Law"],
answer:2
},
{
question:"137. The magnetic flux in a magnetic circuit is directly proportional to:",
options:["Reluctance","Magnetomotive force","Resistance","Length of the magnetic path"],
answer:1
},
{
question:"138. Which factor reduces the reluctance of a magnetic circuit?",
options:["Increasing the air gap","Using a material with high permeability","Increasing the length of the magnetic path","Reducing the cross-sectional area"],
answer:1
},
{
question:"139. A magnetic circuit with a large air gap will have:",
options:["Lower reluctance","Higher reluctance","No reluctance","Infinite permeability"],
answer:1
},
{
question:"140. Which of the following best describes magnetic saturation?",
options:[
"The complete loss of magnetism",
"The maximum magnetic flux density a material can carry",
"The removal of hysteresis",
"The absence of magnetic flux"
],
answer:1
},
{
question:"141. The ability of a magnetic material to store magnetic energy is related to its:",
options:["Permeability","Retentivity","Conductivity","Resistance"],
answer:1
},
{
question:"142. Which of the following is used to determine the B-H curve of a material?",
options:["Experiment","Voltmeter","Ammeter","Wheatstone Bridge"],
answer:0
},
{
question:"143. During a B-H curve experiment, the magnetic field strength is varied by changing the:",
options:["Voltage","Current","Resistance","Power"],
answer:1
},
{
question:"144. The magnetic energy loss in a material is mainly due to:",
options:["Hysteresis","Capacitance","Resistance","Inductance"],
answer:0
},
{
question:"145. Which magnetic material has low coercivity?",
options:["Hard steel","Alnico","Soft iron","Cobalt steel"],
answer:2
},
{
question:"146. Which property makes soft iron suitable for electromagnets?",
options:["High retentivity","Low permeability","High permeability and low coercivity","High resistance"],
answer:2
},
{
question:"147. Which property makes hard steel suitable for permanent magnets?",
options:["Low retentivity","High retentivity and high coercivity","Low permeability","High conductivity"],
answer:1
},
{
question:"148. The magnetic equivalent of electrical conductance is:",
options:["Permeance","Permeability","Reluctance","Flux"],
answer:0
},
{
question:"149. If reluctance increases while MMF remains constant, the magnetic flux will:",
options:["Increase","Decrease","Remain constant","Double"],
answer:1
},
{
question:"150. Which of the following statements is TRUE?",
options:[
"Soft magnetic materials are used for permanent magnets.",
"Hard magnetic materials are used for transformer cores.",
"Soft magnetic materials are suitable for transformer cores because of their low hysteresis loss.",
"Air has a higher permeability than soft iron."
],
answer:2
},
{
question:"151. Which of the following is NOT a soft magnetic material?",
options:["Soft iron","Silicon steel","Ferrite","Hardened steel"],
answer:3
},
{
question:"152. Which property determines how easily a material can be magnetized?",
options:["Retentivity","Permeability","Coercivity","Resistivity"],
answer:1
},
{
question:"153. The formula for magnetomotive force is:",
options:["F = IN","F = B/A","F = ΦS","F = H/B"],
answer:0
},
{
question:"154. The formula for magnetic field strength is:",
options:["H = IN/l","H = Φ/A","H = μ/B","H = F × Φ"],
answer:0
},
{
question:"155. Which quantity is measured in Tesla?",
options:["Magnetic Flux","Magnetic Flux Density","Magnetomotive Force","Reluctance"],
answer:1
},
{
question:"156. If the magnetic flux is 0.8 Wb and the cross-sectional area is 0.2 m², the flux density is:",
options:["0.16 T","1.6 T","4 T","5 T"],
answer:2
},
{
question:"157. A magnetic circuit with low reluctance will:",
options:["Allow magnetic flux to flow easily","Completely block magnetic flux","Reduce magnetomotive force","Produce no magnetic field"],
answer:0
},
{
question:"158. Which of the following has the unit Weber per square metre?",
options:["Magnetic Flux","Magnetic Flux Density","Reluctance","Magnetic Field Strength"],
answer:1
},
{
question:"159. The symbol μ₀ represents:",
options:["Relative permeability","Magnetic flux","Permeability of free space","Magnetic field strength"],
answer:2
},
{
question:"160. Which of the following statements is correct?",
options:[
"Magnetic flux always flows in an open path.",
"Magnetic circuits oppose electric current.",
"Magnetic flux follows a closed magnetic path.",
"Permeability is measured in volts."
],
answer:2
},
{
question:"161. The magnetic equivalent of electromotive force (e.m.f.) is:",
options:["Magnetic flux","Magnetomotive force","Reluctance","Permeability"],
answer:1
},
{
question:"162. Which of the following is the magnetic equivalent of electrical current?",
options:["Magnetic field strength","Magnetic flux","Reluctance","Permeability"],
answer:1
},
{
question:"163. Which law is regarded as the magnetic equivalent of Ohm's Law?",
options:["Faraday's Law","Lenz's Law","Hopkinson's Law","Ampere's Law"],
answer:2
},
{
question:"164. The relationship Φ = F/S indicates that magnetic flux is:",
options:["Directly proportional to MMF","Inversely proportional to MMF","Independent of reluctance","Equal to permeability"],
answer:0
},
{
question:"165. If the reluctance of a magnetic circuit is doubled while MMF remains constant, the magnetic flux will:",
options:["Double","Be halved","Remain unchanged","Become four times"],
answer:1
},
{
question:"166. Which of the following is NOT a unit used in magnetic circuits?",
options:["Tesla","Weber","Henry","Ohm"],
answer:3
},
{
question:"167. A material with high permeability is preferred because it:",
options:["Opposes magnetic flux","Allows magnetic flux to pass easily","Has high electrical resistance","Cannot be magnetized"],
answer:1
},
{
question:"168. The B-H curve of a soft magnetic material is generally:",
options:["Wide","Narrow","Circular","Straight"],
answer:1
},
{
question:"169. A narrow hysteresis loop indicates:",
options:["High hysteresis loss","Low hysteresis loss","High reluctance","High resistance"],
answer:1
},
{
question:"170. Which magnetic material is most suitable for transformer cores because of its narrow hysteresis loop?",
options:["Soft iron","Silicon steel","Hard steel","Alnico"],
answer:1
},
{
question:"171. The main cause of hysteresis loss is:",
options:[
"Alternating magnetization of the core",
"High electrical resistance",
"Mechanical vibration",
"High supply voltage"
],
answer:0
},
{
question:"172. The main purpose of laminating the core of a transformer is to reduce:",
options:[
"Hysteresis loss",
"Eddy current loss",
"Copper loss",
"Mechanical loss"
],
answer:1
},
{
question:"173. Which of the following is NOT a magnetic quantity?",
options:[
"Magnetic flux",
"Magnetic flux density",
"Electric charge",
"Magnetic field strength"
],
answer:2
},
{
question:"174. A magnetic material with high retentivity is suitable for making:",
options:[
"Transformer cores",
"Electromagnets",
"Permanent magnets",
"Relay cores"
],
answer:2
},
{
question:"175. Which property of a magnetic material determines its opposition to demagnetization?",
options:[
"Retentivity",
"Permeability",
"Coercivity",
"Reluctance"
],
answer:2
},
{
question:"176. Which of the following materials has the highest permeability?",
options:[
"Air",
"Wood",
"Soft iron",
"Plastic"
],
answer:2
},
{
question:"177. If the magnetic path length increases while all other factors remain constant, the reluctance will:",
options:[
"Decrease",
"Increase",
"Remain the same",
"Become zero"
],
answer:1
},
{
question:"178. Which of the following quantities has no SI unit?",
options:[
"Magnetic flux",
"Relative permeability",
"Flux density",
"Magnetic field strength"
],
answer:1
},
{
question:"179. The magnetic circuit equivalent of electrical resistance is:",
options:[
"Magnetomotive force",
"Permeability",
"Reluctance",
"Flux"
],
answer:2
},
{
question:"180. Which expression correctly defines relative permeability?",
options:[
"μr = μ/μ₀",
"μr = μ₀/μ",
"μr = B/H",
"μr = Φ/A"
],
answer:0
},
{
question:"181. The magnetic circuit equivalent of electrical conductance is:",
options:[
"Permeance",
"Reluctance",
"Magnetic flux",
"Magnetic field strength"
],
answer:0
},
{
question:"182. Which of the following formulas correctly gives magnetic field strength?",
options:[
"H = F/l",
"H = Φ/A",
"H = μ/B",
"H = B/Φ"
],
answer:0
},
{
question:"183. A magnetic circuit with zero reluctance would allow magnetic flux to:",
options:[
"Stop completely",
"Flow without opposition",
"Decrease to zero",
"Reverse direction"
],
answer:1
},
{
question:"184. Which magnetic property enables a transformer core to be easily magnetized and demagnetized?",
options:[
"High coercivity",
"High permeability",
"High retentivity",
"High resistivity"
],
answer:1
},
{
question:"185. In a magnetic circuit, increasing the cross-sectional area while keeping all other factors constant will:",
options:[
"Increase reluctance",
"Decrease reluctance",
"Have no effect",
"Stop magnetic flux"
],
answer:1
},
{
question:"186. Which of the following best describes a hard magnetic material?",
options:[
"It is easily magnetized and demagnetized",
"It has low coercivity",
"It retains magnetism for a long time",
"It has very low retentivity"
],
answer:2
},
{
question:"187. The slope of the initial B-H curve represents the:",
options:[
"Permeability of the material",
"Magnetic flux",
"Reluctance",
"Magnetomotive force"
],
answer:0
},
{
question:"188. The magnetic energy loss per cycle is equal to the:",
options:[
"Area enclosed by the hysteresis loop",
"Length of the magnetic path",
"Magnetic field strength",
"Cross-sectional area of the core"
],
answer:0
},
{
question:"189. Which experiment is used to determine the hysteresis characteristics of a magnetic material?",
options:[
"B-H curve experiment",
"Ohm's law experiment",
"Kirchhoff's law experiment",
"Wheatstone bridge experiment"
],
answer:0
},
{
question:"190. The main purpose of carrying out magnetic material experiments is to:",
options:[
"Determine magnetic properties",
"Increase electrical resistance",
"Reduce voltage",
"Measure electric current"
],
answer:0
}
{
question:"191. Which of the following is the unit of magnetic flux?",
options:[
"Weber",
"Tesla",
"Ampere-turn",
"Henry"
],
answer:0
},
{
question:"192. The formula used to calculate magnetic flux density is:",
options:[
"B = Φ/A",
"B = A/Φ",
"B = H/μ",
"B = μ/H"
],
answer:0
},
{
question:"193. The permeability of free space is equal to:",
options:[
"2π × 10⁻⁷ H/m",
"3π × 10⁻⁷ H/m",
"4π × 10⁻⁷ H/m",
"5π × 10⁻⁷ H/m"
],
answer:2
},
{
question:"194. Which of the following materials is commonly used to make permanent magnets?",
options:[
"Soft iron",
"Silicon steel",
"Alnico",
"Pure iron"
],
answer:2
},
{
question:"195. Which property allows a magnetic material to retain magnetism after the magnetizing force is removed?",
options:[
"Permeability",
"Retentivity",
"Reluctance",
"Conductivity"
],
answer:1
},
{
question:"196. The opposition offered by a magnetic circuit to the flow of magnetic flux is called:",
options:[
"Resistance",
"Reactance",
"Reluctance",
"Conductance"
],
answer:2
},
{
question:"197. Which of the following statements about soft magnetic materials is TRUE?",
options:[
"They have high coercivity.",
"They are difficult to magnetize.",
"They are easily magnetized and demagnetized.",
"They are mainly used for permanent magnets."
],
answer:2
},
{
question:"198. Which magnetic quantity is represented by the symbol B?",
options:[
"Magnetic field strength",
"Magnetic flux density",
"Magnetomotive force",
"Magnetic flux"
],
answer:1
},
{
question:"199. The magnetic equivalent of Ohm's Law is:",
options:[
"Faraday's Law",
"Hopkinson's Law",
"Lenz's Law",
"Ampere's Law"
],
answer:1
},
{
question:"200. Which of the following best describes a magnetic circuit?",
options:[
"A closed path through which magnetic flux flows",
"An open path through which electric current flows",
"A conductor carrying alternating current only",
"A resistor connected to a power supply"
],
answer:0
}
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