Impedance

What is the total opposition to current flow in an a.c. circuit called?

• Impedance

• Inductance

• Capacitance

• Resistance

In which unit is impedance measured?

• Amps (A)

• Volts (V)

• Ohms (Ω)

• Watts (W)

How is the impedance (Z) calculated in inductive circuits?

• Z = R / X_L

• Z = √(R^2 + X_L^2)

• Z = R + X_L

• Z = R^2 + X_L

What does the power factor (pf) of a circuit equal?

• pf = R / Z

• pf = Z / R

• pf = sinФ

• pf = cosФ

Which formula is used to calculate the current (I) in any a.c. circuit?

• I = V * Z

• I = Z / V

• I = V / Z

• I = V + Z

For a circuit containing R, X_L, and X_C, how is the impedance (Z) calculated?

• Z = √(R^2 + (X_L + X_C)^2)

• Z = √(R^2 + (X_L - X_C)^2)

• Z = R + X_L + X_C

• Z = R^2 + X_L - X_C

What is the phase angle of a circuit the difference between?

• Current and Resistance

• Inductance and Capacitance

• Resistance and Reactance

• Voltage and Current