Q11. | Mutually inductance between two magnetically-coupled coils depends on |
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A. | permeability of the core [Wrong Answer] |
B. | the number of their turns [Wrong Answer] |
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C. | cross-sectional area of their common core [Wrong Answer] |
D. | all of the above [Correct Answer] |
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Q12. | An e.m.f. of 16 volts is induced in a coil of inductance 4 H. The rate of change of current must be |
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A. | 64 A/s [Wrong Answer] |
B. | 32 A/s [Wrong Answer] |
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C. | 16 A/s [Wrong Answer] |
D. | 4 A/s [Correct Answer] |
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Q13. | The co-efficient of coupling between two air core coils depends on |
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A. | self-inductance of two coils only [Wrong Answer] |
B. | mutual inductance between two coils only [Wrong Answer] |
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C. | mutual inductance and self inductance of two coils [Correct Answer] |
D. | none of the above [Wrong Answer] |
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Q14. | A crack in the magnetic path of an inductor will result in |
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A. | unchanged inductance [Wrong Answer] |
B. | increased inductance [Wrong Answer] |
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C. | zero inductance [Wrong Answer] |
D. | reduced inductance [Correct Answer] |
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Q15. | Higher the self-inductance of a coil, | ||||||
A. | lesser its weher-turns [Wrong Answer] |
B. | lower the e.m.f. induced [Wrong Answer] |
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C. | greater the flux produced by it [Wrong Answer] |
D. | longer the delay in establishing steady current through it [Correct Answer] |
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Q16. | A laminated iron core has reduced eddy-current losses because |
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A. | more wire can he used with less D.C. resistance in coil [Wrong Answer] |
B. | the laminations are insulated from each other [Correct Answer] |
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C. | the magnetic flux is concentrated in the air gap of the core [Wrong Answer] |
D. | the laminations are stacked vertically [Wrong Answer] |
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Q17. | The core of a coil has a length of 200 mm. The inductance of coil is 6 mH. If the core length is doubled, all other quantities, remaining the same, the inductance will be |
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A. | 3 mH [Correct Answer] |
B. | 12 mH [Wrong Answer] |
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C. | 24 mH [Wrong Answer] |
D. | 48 mH [Wrong Answer] |
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Q18. | An average Voltage of 10 V is induced in a 250 turns solenoid as a result of a change in flux which occurs in 0.5 second. The total flux change is |
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A. | 20 Wb [Wrong Answer] |
B. | 2 Wb [Wrong Answer] |
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C. | 0.2 Wb [Wrong Answer] |
D. | 0.02 Wb [Correct Answer] |
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Q19. | In an iron cored coil the iron core is removed so that the coil becomes an air cored coil. The inductance of the coil will |
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A. | increase [Wrong Answer] |
B. | decrease [Correct Answer] |
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C. | remain the same [Wrong Answer] |
D. | initially increase and then decrease [Wrong Answer] |
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Q20. | The co-efficient of self-inductance for a coil is given as |
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A. | NI/Φ [Wrong Answer] |
B. | NΦ/I [Correct Answer] |
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C. | NI2/Φ [Wrong Answer] |
D. | NΦ/I2 [Wrong Answer] |
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