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Alternating current lead the applied e.m.f. by p/2 when the circuit consists of
  • a)
    only resistance
  • b)
    only capacitor
  • c)
    only an inductance coil
  • d)
    capacitor and resistance both
Correct answer is option 'B'. Can you explain this answer?
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Alternating current lead the applied e.m.f. by p/2 when the circuit co...
Explanation:

AC Circuit with Capacitor

When an AC circuit contains only a capacitor, the current leads the applied emf by p/2.

- In an AC circuit, the voltage across the capacitor changes with time.
- As the voltage across the capacitor changes, the capacitor charges and discharges.
- When the voltage across the capacitor is increasing, the current flowing through the capacitor is in the opposite direction of the voltage.
- When the voltage across the capacitor is decreasing, the current flowing through the capacitor is in the same direction as the voltage.
- Therefore, the current leads the voltage by p/2 in an AC circuit with only a capacitor.

Mathematical Explanation

- In an AC circuit with only a capacitor, the impedance of the capacitor is given by Zc = 1/jwc, where j is the imaginary unit, w is the angular frequency, and C is the capacitance.
- The current through the capacitor is given by Ic = V/Zc, where V is the applied emf.
- Substituting Zc, we get Ic = jwCV.
- The current leads the voltage by p/2, which means that the phase angle between the current and voltage is p/2 or 90 degrees.

Conclusion

Thus, we can conclude that in an AC circuit with only a capacitor, the current leads the applied emf by p/2 or 90 degrees.
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Alternating current lead the applied e.m.f. by p/2 when the circuit co...
Capacitor circuit current leads by voltage pi/2...inductor circuit voltage leads by current pi/2...
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Alternating current lead the applied e.m.f. by p/2 when the circuit consists ofa)only resistanceb)only capacitorc)only an inductance coild)capacitor and resistance bothCorrect answer is option 'B'. Can you explain this answer?
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