Chapter 19: Alternating Current Flashcards
What is alternating current (AC)?
“Alternating current (AC) is an electric current that reverses direction periodically
What is the frequency of an AC signal?
“The frequency of an AC signal is the number of complete cycles of current flow per second
What is the equation for the RMS value of current?
“The root mean square (RMS) value of current is given by I_RMS = I_max / √2
What is the equation for the RMS value of voltage?
“The RMS value of voltage is given by V_RMS = V_max / √2
What is the difference between peak value and RMS value in AC?
“The peak value is the maximum value of current or voltage
What is the power in an AC circuit?
“The power in an AC circuit is given by P = V_RMS * I_RMS * cos(φ)
What is the concept of impedance?
“Impedance (Z) is the total opposition to current flow in an AC circuit
What is the formula for impedance in an RLC circuit?
“In an RLC circuit
What is inductive reactance?
“Inductive reactance (X_L) is the opposition to AC due to an inductor
What is capacitive reactance?
“Capacitive reactance (X_C) is the opposition to AC due to a capacitor
What is resonance in an AC circuit?
“Resonance in an AC circuit occurs when the inductive reactance equals the capacitive reactance (X_L = X_C)
What is the power factor?
“The power factor is the ratio of real power (P) to apparent power (S) in an AC circuit
What is the difference between real power and apparent power?
“Real power (P) is the power actually consumed by the circuit
What is the phase difference between current and voltage in a purely resistive AC circuit?
“In a purely resistive AC circuit
What is the phase difference between current and voltage in a purely inductive AC circuit?
“In a purely inductive AC circuit
What is the phase difference between current and voltage in a purely capacitive AC circuit?
“In a purely capacitive AC circuit
What is the concept of a transformer?
“A transformer is an electrical device that changes the voltage in an AC circuit through electromagnetic induction
What is the equation for the transformer?
“The transformer equation relates the voltages and currents of the primary and secondary coils: V₁/V₂ = N₁/N₂ = I₂/I₁
What is the efficiency of a transformer?
“The efficiency of a transformer is the ratio of output power to input power
What is the concept of power loss in transmission lines?
“Power loss in transmission lines is due to the resistance of the wires
