MCQ
In R - L - C series circuit, the potential differences across each element is 20V. Now the value of the resistance alone is doubled, then P.D. across R, L and C respectively.
  • A
    20V, 10V, 10V
  • B
    20V, 20V, 20V
  • C
    20V, 40V, 40V
  • D
    10V, 20V, 20V

Answer

  1. 20V, 10V, 10V

Explanation:

Circuit is at resonance (VL = VC)

$\therefore$ circuit is purely resistance

Resistance is doubled, current in the circuit is half the initial value

$\therefore$ New current $\text{I′}=\frac{\text{I}}{2}$

$\therefore$ VR = 20V (equal to applied voltage earlier)

 VL = 10V

 VC = 10V

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