AC & DC Simplified Revision Notes for GCSE AQA Physics Combined Science

Revision notes with simplified explanations to understand AC & DC quickly and effectively.

Learn about Series & Parallel Circuits for your GCSE Physics Combined Science Exam. This Revision Note includes a summary of Series & Parallel Circuits for easy recall in your Physics Combined Science exam

257+ students studying

2.2.4 AC & DC

Direct Current (DC)

infoNote

A direct current (DC) is an electric current that constantly flows in only one direction, at a constant voltage. On a graph plotting current or voltage against time for direct current, the line would be horizontal.

Alternating Current (AC)

infoNote

An alternating current (AC) is an electric current that reverses direction at regular intervals.

infoNote

On a graph plotting current or voltage against time for AC, the values will alternate between positive and negative. This shows the direction that the current flows.

Benefit: Alternating current is used for long-distance energy transmission because it can be transferred more efficiently - It is very easy to use a transformer to increase or decrease the potential difference (P.D.).
Specifications:
- Frequency: 50 Hz
- P.D.: 230V In the UK, the mains electricity supply operates at a frequency of 50 Hz with a potential difference of 230 V. This means the voltage fluctuates between +230 V and -230 V, causing the current to change direction 50 times per second.

Oscilloscope

Function: Used to see the pattern of an electrical current.

infoNote

Formula for Frequency:

\text{frequency} = \frac{1}{t}

Variables:
$t$ : Time of one cycle

Graphs

DC Supply: Current remains constant over time.
AC Supply: Current changes direction periodically over time.

500K+ Students Use These Powerful Tools to Master AC & DC For their GCSE Exams.

Enhance your understanding with flashcards, quizzes, and exams—designed to help you grasp key concepts, reinforce learning, and master any topic with confidence!

70 flashcards

Flashcards on AC & DC

Revise key concepts with interactive flashcards.

Try Physics Combined Science Flashcards

7 quizzes

Quizzes on AC & DC

Test your knowledge with fun and engaging quizzes.

Try Physics Combined Science Quizzes

29 questions

Exam questions on AC & DC

Boost your confidence with real exam questions.

Try Physics Combined Science Questions