SIMPLE ALTERNATING CURRENT

Open Ended

In what ways does alternating current (AC) differ from direct current (DC), and why might these differences be important in everyday life?

Multiple Choice

Why is alternating current (AC) preferred for domestic power supply in countries like Nigeria?

• Because AC can be easily transformed to different voltages for efficient long-distance transmission.

• Because AC is safer than DC.

• Because AC is cheaper to produce than DC.

• Because AC does not change direction.

Multiple Choice

Which of the following is a key characteristic of a simple AC circuit?

• Current and voltage remain constant over time.

• Both magnitude and direction of current and voltage change continuously.

• It only contains a DC source.

• It does not require a load.

Open Ended

List and briefly explain two characteristics of alternating current that are important for power calculations.

Multiple Select

Which of the following statements about the components of an AC circuit are correct?

• The resistor causes current to lag voltage by 90°.

• The inductor causes current to lag voltage by 90°.

• The capacitor causes current to lead voltage by 90°.

• The AC power supply provides a constant voltage.

Open Ended

Explain how the diagrams of simple AC circuits with resistors and RC circuits help in understanding the behavior of current and voltage in AC circuits.

Fill in the Blank

In a pure resistive AC circuit, voltage and current are ___ phase.

Multiple Choice

Which of the following is NOT an application of alternating current (AC)?

• Powering lights and appliances.

• Long-distance power transmission.

• Operation of transformers and motors.

• Charging a car battery directly.

Multiple Choice

Which device combination is used to produce and observe sinusoidal voltage in a classroom demonstration?

• Function generator and oscilloscope

• Multimeter and resistor

• Battery and ammeter

• Transformer and voltmeter

Open Ended

Explain how phasor rotation helps in understanding phase differences in AC circuits.

Fill in the Blank

AC remains the foundation of modern electrical ___ systems.

Multiple Choice

What is one key difference between Alternating Current (AC) and Direct Current (DC)?

• AC reverses direction periodically, while DC flows in one direction only.

• AC is used only in batteries, while DC is used in power grids.

• AC cannot be transmitted over long distances, while DC can.

• AC has a constant magnitude, while DC changes sinusoidally.