Electrical Relationships in AC Circuits

What is the definition of Alternating Current?

• A constant flow of electrons at a fixed voltage

• A flow of electrons that moves in one direction only

• A flow of electrons that decreases over time

• A flow of electrons that rises to a maximum value in one direction, falls back to zero, and repeats in the opposite direction

What does RMS Value represent in AC circuits?

• The AC value of an equivalent DC quantity that would deliver the same average power to the same resistor

• The total energy consumed by the circuit

• The average value of the current over one cycle

• The maximum value of the current

What is the formula to calculate the average current in AC?

• Average current = Peak x 0.5

• Average current = Peak x 0.707

• Average current = Peak x 0.637

• Average current = Peak / 2

What does a capacitor do in an electrical circuit?

• Converts AC to DC

• Stores electrical charge when a voltage is applied across it

• Induces voltage to maintain current flow

• Opposes the flow of electric current

What is the unit of inductance?

• Ohms (Ω)

• Farads (F)

• Henrys (H)

• Volts (V)

What is the power factor in AC circuits?

• The ratio of real power to reactive power

• The efficiency of the power supply

• The ratio of real power to apparent power

• The total energy consumed by the circuit

How is the frequency of an AC signal measured?

• Ohms

• Hertz (Hz)

• Amps

• Volts

What property does inductance oppose?

• Capacitance

• Changes in the current flowing through it

• Resistance

• Voltage

What is the effect of a transformer on power?

• It reduces the overall power consumption

• It only increases the voltage

• It converts real power to reactive power

• It deals with both real and reactive power

Why are transformers rated in kVA?

• Because it is a more cost-effective measurement

• Because it reflects their capacity to handle both real and reactive power

• Because it reflects their capacity to handle only reactive power

• Because it reflects their capacity to handle only real power