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#### Electromagnetic Induction and Alternating Current - Two Marks Study Materials

12th Standard EM

Reg.No. :
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Physics

Time : 01:00:00 Hrs
Total Marks : 30
15 x 2 = 30
1. What is meant by electromagnetic induction?

2. State Faraday’s laws of electromagnetic induction.

3. Mention the ways of producing induced emf.

4. What do you mean by self-induction?

5. List out the advantages of stationary armature-rotating field system of AC generator.

6. How will you define RMS value of an alternating current?

7. What is meant by wattles current?

8. What are LC oscillations?

9. Explain the use of transformers in long distance transmission of electric power

10. What is inductive reactance X1? How does it depend on frequencei Give its unit.

11. Draw a graph showing variation of current with changing frequency of applied voltage in a series LCR circuit for two different values of resistance R1 & R2 (I1 > I2) fr - resonant frequency.

12. What is the signifienance of Quality factor or Q-factor.

13. State the law that gives the polarity of the induced emf.

14. Draw a graph showing the variation of reactance of
(i) a capacitor and
(ii) an inductor with the frequency of an a.c circuit.

15. Does the current in an a.c circuit lag lead or remain in phase with the applied voltage. When
(i)  γ =  γr
(ii)  γ <  γr
(iii)  γ >  γr
Where  γr is the resonant frequency?