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Physics Chapter 31: AC Circuits and Related Concepts

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Terms in this set (15)

  • What is the symbol and unit for angular frequency?
    Symbol: \(\omega\) (omega), Unit: radians per second (rad/s).
  • What is inductive reactance and its unit?
    Inductive reactance is the opposition to current by an inductor, symbol \(X_L\), measured in ohms (Ω).
  • What is capacitive reactance and its unit?
    Capacitive reactance is the opposition to current by a capacitor, symbol \(X_C\), measured in ohms (Ω).
  • What is impedance and its unit?
    Impedance is the total opposition to AC current in a circuit, symbol \(Z\), measured in ohms (Ω).
  • What is phase shift and its unit?
    Phase shift is the angular difference between voltage and current, symbol \(\phi\) (phi), measured in degrees.
  • Write the equations defining rms voltage and current.
    \(I_{rms} = \frac{I_0}{\sqrt{2}}\) and \(V_{rms} = \frac{V_0}{\sqrt{2}}\).
  • What is the phase relationship between emf and current in inductors and capacitors?
    In an inductor, emf leads current by 90°. In a capacitor, current leads emf by 90°.
  • Write Ohm's law for inductors and the formula for inductive reactance.
    \(V_L = X_L I\) and \(X_L = \omega L\).
  • Write Ohm's law for capacitors and the formula for capacitive reactance.
    \(V_C = X_C I\) and \(X_C = \frac{1}{\omega C}\).
  • Write Ohm's law for an RLC circuit and the formula for impedance.
    \(V_{tot} = Z I_{tot}\) with \(Z = \sqrt{R^2 + (X_L - X_C)^2}\).
  • Write the equation for average power in an RLC circuit.
    \(P_{avg} = V_{rms} \cdot I_{rms} \cdot \cos(\phi)\).
  • Write the equation defining the resonance angular frequency in an LC circuit.
    \(\omega_0 = \frac{1}{\sqrt{LC}}\).
  • Write the energy conservation equation in an LC circuit.
    \(\frac{1}{2} L i^2 + \frac{q^2}{2C} = \text{const.}\)
  • Write the relationships between angular frequency, linear frequency, and period.
    \(\omega = 2 \pi f = \frac{2 \pi}{T}\).
  • Write the conversion relationship between radians, revolutions, and degrees.
    \(2 \pi \text{ rad} = 1 \text{ rev} = 360^\circ\).