Differences between Direct and Alternating Potential Difference

The video tutorial explains the differences between direct and alternating currents. Direct current (DC) flows in one direction, while alternating current (AC) changes direction periodically. The video uses graphs to illustrate these concepts, showing how potential difference behaves over time for each type of current. It also covers the calculation of frequency and peak potential difference in AC, using the UK standard of 230 volts and 50 Hertz as examples. The tutorial concludes by explaining how these concepts apply to real-world applications like batteries and mains electricity.

What is the main characteristic of a direct current?

• It flows in one direction only.

• It changes direction periodically.

• It has a constant frequency.

• It is used in mains electricity.

Which of the following devices typically uses direct current?

• Electric fan

• Television

• Refrigerator

• Battery-powered torch

In a direct current graph, what does a potential difference that never goes below zero indicate?

• The current is direct.

• The current is alternating.

• The current is constant.

• The potential difference is negative.

What does the frequency of an alternating current waveform indicate?

• The resistance in the circuit

• The voltage of the current

• The number of times the current changes direction per second

• The speed of the current

In the UK, what is the standard frequency of mains electricity?

• 30 Hertz

• 40 Hertz

• 60 Hertz

• 50 Hertz