# Physics - Circuits

> Source: https://ollybritton.com/notes/a-level/physics/topics/circuits/ · Updated: 2024-08-25 · Tags: physics, school, year-1

##### What is the symbol for a wire in a circuit??
![PHOTO WIRE CIRCUIT](paste-5419f3d6b40ae6922dcefd7089710faaece2021a.jpg)

##### What is the symbol for a resistor in a circuit??
![PHOTO RESISTOR CIRCUIT](paste-2ceba9c5d53134cbc7348ac576c3faf8b87fe75d.jpg)

##### What is the symbol for a light bulb in a circuit??
![PHOTO LIGHT BULB CIRCUIT](paste-dc9de5096efe636ca5362a10ac8006f01f78cb4c.jpg)

##### What is the symbol for a cell in a circuit??
![PHOTO CELL CIRCUIT](paste-387d219ac3d045437313131e7b562dc84edb5478.jpg)

##### What is the symbol for a battery in a circuit??
![PHOTO BATTERY CIRCUIT](paste-d9660635f26ab34fd986667177949cb8f4b6914e.jpg)

##### What is the symbol for a switch in a circuit??
![PHOTO SWITCH CIRCUIT](paste-9c0ea3a7c3d69ae5c893755969826813055a0cf8.jpg)

##### ![PHOTO CELL CIRCUIT](paste-387d219ac3d045437313131e7b562dc84edb5478.jpg) Which is the positive terminal??
The one on the left.

##### ![PHOTO CELL CIRCUIT](paste-387d219ac3d045437313131e7b562dc84edb5478.jpg) What is the technique for remembering the positive and negative terminals on a cell??
You can draw a "P" on the big positive side.

### 2021-01-18
##### What is the symbol for a diode in a circuit??
![PHOTO CIRCUIT DIODE](circuit-diode.png)

##### ![PHOTO CIRCUIT DIODE](circuit-diode.png) What does this represent in a circuit??
A diode.

##### What is the symbol for a resistor in a circuit??
![PHOTO CIRCUIT RESISTOR](circuit-resistor.png)

##### ![PHOTO CIRCUIT RESISTOR](circuit-resistor.png) What does this represent in a circuit??
A resistor.

##### What is the symbol for a variable-resistor in a circuit??
![PHOTO CIRCUIT VARIABLE-RESISTOR](circuit-variable-resistor.png)

##### ![PHOTO CIRCUIT VARIABLE-RESISTOR](circuit-variable-resistor.png) What does this represent in a circuit??
A variable resistor.

##### What is the symbol for a fuse in a circuit??
![PHOTO CIRCUIT FUSE](circuit-fuse.png)

##### ![PHOTO CIRCUIT FUSE](circuit-fuse.png) What does this represent in a circuit??
A fuse.

##### What is the symbol for a voltmeter in a circuit??
![PHOTO CIRCUIT VOLTMETER](circuit-voltmeter.png)

##### ![PHOTO CIRCUIT VOLTMETER](circuit-voltmeter.png) What does this represent in a circuit??
A voltmeter.

##### What is the symbol for a ammeter in a circuit??
![PHOTO CIRCUIT AMMETER](circuit-ammeter.png)

##### ![PHOTO CIRCUIT AMMETER](circuit-ammeter.png) What does this represent in a circuit??
An ammeter.

##### What is the symbol for a thermistor in a circuit??
![PHOTO CIRCUIT THERMISTOR](circuit-thermistor.png)

##### ![PHOTO CIRCUIT THERMISTOR](circuit-thermistor.png) What does this represent in a circuit??
A thermistor.

##### What is the symbol for a led in a circuit??
![PHOTO CIRCUIT LED](circuit-led.png)

##### ![PHOTO CIRCUIT LED](circuit-led.png) What does this represent in a circuit??
An LED.

##### What is the symbol for a capacitor in a circuit??
![PHOTO CIRCUIT CAPACITOR](circuit-capacitor.png)

##### ![PHOTO CIRCUIT CAPACITOR](circuit-capacitor.png) What does this represent in a circuit??
A capacitor.

##### Should you connect an ammeter in series or in parallel??
In series.

##### Should you connect a voltmeter in series or in parallel??
In parallel.

### 2021-01-29
##### Which way does a diode need to be pointing to let current through??
In the direction of the conventional current.

##### What is the threshold voltage for a silicon diode??
About $0.7V$.

### 2021-02-04
##### How do fuses work??
They contain a wire which melts if the current is too high.

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