OCR · A-Level · Physics
Course version: H556 · Version from Sept 2015
Circuit symbols: (a) circuit symbols
Circuit symbols are the standardised shorthand used to draw electrical circuits.
Checked against the OCR H556 specification (opens in a new tab) on .
- Point 1 of 2
- 4 key terms
Study notes
From the checked teaching notes for this specification point.
The idea
Circuit symbols are the standardised shorthand used to draw electrical circuits. You must recognise and reproduce the symbols for a cell, battery, d.c. power supply, a.c. power supply, switch, filament lamp, resistor, variable resistor, thermistor, light-dependent resistor, ammeter, voltmeter, diode, light-emitting diode, capacitor and earth. Each symbol encodes the component's function: a cell has a long line for the positive terminal and a short thick line for the negative terminal, an ammeter is a circle containing A and is connected in series, and a voltmeter is a circle containing V and is connected in parallel. In a multiple-choice question you may be asked to identify a symbol, match a symbol to its name, or spot an incorrectly drawn symbol.
What earns the marks
- Recognises the standard symbol for each named component, including cell, battery, switch, lamp, resistor, variable resistor, thermistor, LDR, ammeter, voltmeter, diode, LED, capacitor and earth.
- Distinguishes a cell from a battery by the number of long and short line pairs.
- Identifies the ammeter symbol as a circle containing A and the voltmeter symbol as a circle containing V.
- Recognises the diode triangle with a bar and the LED symbol with arrows indicating emitted light.
- Identifies the variable resistor as a resistor with an arrow through it and the thermistor and LDR by their modifying arrows.
Common mistakes and how to put them right
Drawing a cell with two identical lines.
Put it right: The positive terminal is the longer thinner line and the negative terminal is the shorter thicker line.
Confusing the ammeter and voltmeter symbols.
Put it right: The letter inside the circle identifies the meter, and their connection positions differ.
Drawing a diode without the bar or with the triangle pointing the wrong way.
Put it right: The bar marks the cathode and the triangle points in the conventional current direction.
Omitting the arrows on an LED or LDR symbol, which are needed to distinguish them from a plain diode or resistor.
Exam tips
- Learn symbols by drawing them from memory in a table with the component name beside each one.
- Check the direction of the triangle and the position of the bar when drawing a diode.
- Remember that ammeters go in series and voltmeters in parallel, which is reflected in how their symbols are placed.
- Practise spotting deliberately wrong symbols, such as a cell with equal-length lines.
Try the lesson
The start of the Circuit symbols: (a) circuit symbols lesson, made from checked teaching notes for this specification point.
Listen
Circuit symbols are the standardised shorthand used to draw electrical circuits. You must recognise and reproduce the symbols for a cell, battery, d.c. power supply, a.c. power supply, switch, filament lamp, resistor, variable resistor, thermistor, light-dependent resistor, ammeter, voltmeter, diode, light-emitting diode, capacitor and earth. Each symbol encodes the component's function: a cell has a long line for the positive terminal and a short thick line for the negative terminal, an ammeter is a circle containing A and is connected in series, and a voltmeter is a circle containing V and is connected in parallel. In a multiple-choice question you may be asked to identify a symbol, match a symbol to its name, or spot an incorrectly drawn symbol. A strong answer earns marks for these points. Recognises the standard symbol for each named component, including cell, battery, switch, lamp, resistor, variable resistor, thermistor, LDR, ammeter, voltmeter, diode, LED, capacitor and earth. Distinguishes a cell from a battery by the number of long and short line pairs. Identifies the ammeter symbol as a circle containing A and the voltmeter symbol as a circle containing V. Recognises the diode triangle with a bar and the LED symbol with arrows indicating emitted light. Exam tip: Learn symbols by drawing them from memory in a table with the component name beside each one.
Key words
Say what each word means before you turn the card.
Standard circuit symbols
Try answering aloud or in your head before turning the card.
Component identification
Try answering aloud or in your head before turning the card.
Series and parallel meter connection
Try answering aloud or in your head before turning the card.
Accurate scientific drawing
Try answering aloud or in your head before turning the card.
See every definition
- Standard circuit symbols
- The standardised shorthand used to draw electrical circuits, which you must recognise and reproduce for named components.
- Component identification
- Being asked to identify a symbol, match a symbol to its name, or spot an incorrectly drawn symbol in a multiple-choice question.
- Series and parallel meter connection
- An ammeter is connected in series, while a voltmeter is connected in parallel.
- Accurate scientific drawing
- Drawing symbols correctly, such as checking the direction of the triangle and the position of the bar when drawing a diode.
There is more to this lesson
The full lesson goes on to check your understanding and help you earn the marks. Create a free account to carry on, with your progress saved.
A week of Premium from your first lesson · Then the free plan continues · No card, no charge
Test your understanding of Circuit symbols: (a) circuit symbols
Active recall beats re-reading. Take an instant quiz now to test what you’ve learned and lock it into long-term memory.
A week of Premium from your first lesson · Then the free plan continues · No card, no charge