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.
- A20V, 10V, 10V
- B20V, 20V, 20V
- C20V, 40V, 40V
- D10V, 20V, 20V
✓
Answer
- 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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