MCQOPTIONS
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MCQOPTIONS
This section includes 81 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering Questions knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
Which of the following type of materials are not very important for engineering applications ? |
| A. | Ferromagnetic |
| B. | Paramagnetic |
| C. | Diamagnetic |
| D. | None of the above |
| Answer» D. None of the above | |
| 52. |
Which of the following materials are diamagnetic ? |
| A. | Silver |
| B. | Copper |
| C. | Silver and copper |
| D. | Iron |
| Answer» D. Iron | |
| 53. |
The attraction capacity of electromagnet will increase if the_______________? |
| A. | core length increases i |
| B. | core area increases |
| C. | flux density decreases |
| D. | flux density increases |
| Answer» E. | |
| 54. |
Hysteresis loop in case of magnetically hard materials is more in shape as compared to magnetically soft materials |
| A. | circular |
| B. | triangular |
| C. | rectangular |
| D. | none of the above |
| Answer» D. none of the above | |
| 55. |
A keeper is used to_____________? |
| A. | change the direction of magnetic lines |
| B. | amplify flux |
| C. | restore lost flux |
| D. | provide a closed path for flux |
| Answer» E. | |
| 56. |
The change of cross-sectional area of conductor in magnetic field will affect______________? |
| A. | reluctance of conductor |
| B. | resistance of conductor |
| C. | A. and B. both in the same way |
| D. | none of the above |
| Answer» D. none of the above | |
| 57. |
The uniform magnetic field is______________? |
| A. | the field of a set of parallel conductors |
| B. | the field of a single conductor |
| C. | the field in which all lines of magnetic flux are parallel and equidistant |
| D. | none of the above |
| Answer» D. none of the above | |
| 58. |
A certain amount of current flows through a ring-shaped coil with fixed number of turns. How does the magnetic induction B varies inside the coil if an iron core is threaded into coil without dimensional change of coil ? |
| A. | Decreases |
| B. | Increases |
| C. | Remains same |
| D. | First increases and then decreases depending on the depth of iron in¬sertion |
| Answer» C. Remains same | |
| 59. |
The magneto-motive force is______________? |
| A. | the voltage across the two ends of exciting coil |
| B. | the flow of an electric current |
| C. | the sum of all currents embraced by one line of magnetic field |
| D. | the passage of magnetic field through an exciting coil |
| Answer» D. the passage of magnetic field through an exciting coil | |
| 60. |
The initial permeability of an iron rod is________________? |
| A. | the highest permeability of the iron rod |
| B. | the lowest permeability of the iron rod |
| C. | the permeability at the end of the iron rod |
| D. | the permeability almost in non-magnetised state |
| Answer» E. | |
| 61. |
What will be the magnetic potential difference across the air gap of 2 cm length in magnetic field of 200 AT/m ? |
| A. | 2 AT |
| B. | 4 AT |
| C. | 6 AT |
| D. | 10 AT |
| Answer» C. 6 AT | |
| 62. |
If a copper disc is rotated rapidly below a freely suspended magnetic needle, the magnetic needle shall start rotating with a velocity? |
| A. | less than that of disc but in opposite direction |
| B. | equal to that of disc and in the same direction |
| C. | equal to that of disc and in the opposite direction |
| D. | less than that of disc and in the same direction |
| Answer» E. | |
| 63. |
The Biot-savart’s law is a general modification of_______________? |
| A. | Kirchhoffs law |
| B. | Lenz’s law |
| C. | Ampere’s law |
| D. | Faraday’s laws |
| Answer» D. Faraday’s laws | |
| 64. |
The materials are a bit inferior conductors of magnetic flux than air |
| A. | ferromagnetic |
| B. | paramagnetic |
| C. | diamagnetic |
| D. | dielectric |
| Answer» D. dielectric | |
| 65. |
What will be the current passing through the ring shaped air cored coil when number of turns is 800 and ampere turns are 3200 ? |
| A. | 2 |
| B. | 4 |
| C. | 6 |
| D. | 8 |
| Answer» C. 6 | |
| 66. |
A permanent magnet______________? |
| A. | attracts some substances and repels others |
| B. | attracts all paramagnetic substances and repels others |
| C. | attracts only ferromagnetic substances |
| D. | attracts ferromagnetic substances and repels all others |
| Answer» B. attracts all paramagnetic substances and repels others | |
| 67. |
he retentivity (a property) of material is useful for the construction of_______________? |
| A. | permanent magnets |
| B. | transformers |
| C. | non-magnetic substances |
| D. | electromagnets |
| Answer» B. transformers | |
| 68. |
In a simple magnetic field the strength of magnet flux_______________? |
| A. | is constant and has same value in energy part of the magnetic field |
| B. | increases continuously from initial value to final value |
| C. | decreases continuously from initial value to final value |
| D. | first increases and then decreases till it becomes zero |
| Answer» E. | |
| 69. |
Main causes of noisy solenoid are______________? |
| A. | strong tendency of fan out of laminations at the end caused by repulsion among magnetic lines of force |
| B. | uneven bearing surface, caused by dirt or uneven wear between moving and stationary parts |
| C. | both of above |
| D. | none of the above |
| Answer» D. none of the above | |
| 70. |
The susceptibility of paramagnetic materials generally lies between____________? |
| A. | KT3 and 1CT6 |
| B. | 1CT3 and 1CT7 |
| C. | KT4 and KT8 |
| D. | 10″2 and KT5 |
| Answer» B. 1CT3 and 1CT7 | |
| 71. |
Core of an electromagnet should have____________? |
| A. | low coercivity |
| B. | high susceptibility |
| C. | both of the above |
| D. | none of the above |
| Answer» D. none of the above | |
| 72. |
The relative permeability of materials is not constant |
| A. | diamagnetic |
| B. | paramagnetic |
| C. | ferromagnetic |
| D. | insulating |
| Answer» D. insulating | |
| 73. |
A rectangular magnet of magnetic moment M is cut into two piece of same length, the magnetic moment of each piece will be______________? |
| A. | M |
| B. | M/2 |
| C. | 2 M |
| D. | M/4 |
| Answer» C. 2 M | |
| 74. |
The magnetic reluctance of a material______________? |
| A. | decreases with increasing cross sectional area of material |
| B. | increases with increasing cross-sec-tional area of material |
| C. | does not vary with increasing cross-sectional area of material |
| D. | any of the above |
| Answer» B. increases with increasing cross-sec-tional area of material | |
| 75. |
Magnetic moment is a_____________? |
| A. | pole strength |
| B. | universal constant |
| C. | scalar quantity |
| D. | vector quantity |
| Answer» E. | |
| 76. |
For which of the following materials the net magnetic moment should be zero ? |
| A. | Diamagnetic materials |
| B. | Ferrimagnetic materials |
| C. | Antiferromagnetic materials |
| D. | Antiferrimagnetic materials |
| Answer» D. Antiferrimagnetic materials | |
| 77. |
The unit of flux is the same as that of_______________? |
| A. | reluctance |
| B. | resistance |
| C. | permeance |
| D. | pole strength |
| Answer» E. | |
| 78. |
Magnetism of a magnet can be destroyed by_____________? |
| A. | heating |
| B. | hammering |
| C. | by inductive action of another magnet |
| D. | by all above methods |
| Answer» E. | |
| 79. |
Susceptibility is positive for______________? |
| A. | non-magnetic substances |
| B. | diamagnetic substances |
| C. | ferromagnetic substances |
| D. | none of the above |
| Answer» D. none of the above | |
| 80. |
The commonly used material for shielding or screening magnetism is____________? |
| A. | copper |
| B. | aluminium |
| C. | soft iron |
| D. | brass |
| Answer» D. brass | |
| 81. |
When a magnet is in motion relative to a coil the induced e.m.f. does not depend upon____________? |
| A. | resistance of the coil |
| B. | motion of the magnet |
| C. | number of turns of the coil |
| D. | pole strength of the magnet |
| Answer» B. motion of the magnet | |