Active and Reactive Power Concepts

What is the formula for Active Current (I_R)?

• I sin(φ)

• I cos(φ)

• I^2R

• IV

In a phasor diagram, I lags V by what angle?

• φ

• 180 degrees

• 90 degrees

• 0 degrees

What is the formula for Reactive Power (Q)?

• I^2R

• V^2/R

• IVsin(φ)

• IVcos(φ)

What does the term 'apparent power' refer to?

• P + jQ

• P - jQ

• P^2 + Q^2

• P/Q

At resonance in a Series RLC circuit, what is the relationship between X_L and X_C?

• X_L > X_C

• X_L + X_C = 0

• X_L < X_C

• X_L = X_C

What happens to the circuit below the resonant frequency (f_r)?

• It has no effect

• It is inductive and lagging

• It is purely resistive

• It is capacitive and leading

What is the Q factor in a resonant circuit?

• The ratio of reactive power to active power

• The ratio of voltage across the inductor to the voltage across the resistor

• The ratio of resistance to reactance

• The bandwidth of the circuit

In a parallel RLC circuit, what changes when voltage is converted to current?

• Resistance to reactance

• Impedance to admittance

• Resistance to conductance

• Reactance to resistance

What is the formula for the resonant frequency (f_r) in a parallel circuit?

• f_r = 1/(2πC)

• f_r = 1/(2πL)

• f_r = 1/(2π√(LC))

• f_r = R/(2πL)

What is the stored energy in a capacitor given by?

• 0.5LI^2

• 0.5CV^2

• LI

• CV