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Why is the use of a capacitor of variabl...

Why is the use of a capacitor of variable capacitance less costly than the use of a variable resistance for regulating the speed of an electric fan?

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CHHAYA PUBLICATION-ALTERNATING CURRENT -EXERCISE ( Short Answer Type-I)
  1. The number of turns in the coil of an AC generator are 100 and its cro...

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  2. What is the form factor of a sinsoidal alternating current.How can it ...

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  3. The inductance of a resistanceless coil is 0.5 henry. In the coil, the...

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  4. What type of voltmeters or ammeters are used for measuring alternating...

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  5. Why a moving coil galvanometer cannot be used with an alternating cur...

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  6. Write down the conditions for which there will be no phase difference ...

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  7. Why does a series LCR circuit conneted to a DC source register zero cu...

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  8. In a circuit, the frequency is f= 1000/2π ​ Hz ​ and the indu...

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  9. Show with a vector diagram the phase relations among the quantities re...

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  10. What remedial steps are to be taken to minimise damping in LC oscillat...

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  11. Show that a purely capacitative ac circuit dissipates no power.

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  12. Show that a purely inductive ac circuit dissipates no power.

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  13. Why is the use of a capacitor of variable capacitance less costly than...

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  14. How would you explain wattless current in view of the law of conservat...

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  15. How does an LC oscillations behave in a closed LC circuit which includ...

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  16. Explain whether the rms voltages are always the same for two alternati...

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  17. Prove that high frequency ac can pass through a pure capacitor easily ...

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  18. An alternating voltage E=E0sinomegat is applied across an inductor L. ...

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