NCERT Physics Class 12 Exemplar Ch 7 Alternating Current Part 2 (For CBSE, ICSE, IAS, NET, NRA 2022)

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18 In series LCR circuit, the plot of is shown in Figure. Find the bandwidth and mark in the figure.

LCR Circuit- I (Max) - Find Bandwidth

Ans:

  • Bandwidth corresponds to frequencies at which .
  • It is shown in the Fig.

LCR Circuit- Plot of I (Max)

19 The alternating current in a circuit is described by the graph shown in Figure. Show rms current in this graph.

Alternating Current Rms Graph

Ans:

(Shown in Fig. by dotted line)

Alternating Current Described by the Graph

20 How does the sign of the phase angle , by which the supply voltage leads the current in an LCR series circuit, change as the supply frequency is gradually increased from very low to very high values.

Ans:

  • From negative to zero to positive; zero at resonant frequency