Physics - Circuits

OCR A-Level Physics 2022


Basic circuit symbols

What is the symbol for a wire in a circuit?

What is the symbol for a resistor in a circuit?

What is the symbol for a light bulb in a circuit?

What is the symbol for a cell in a circuit?

What is the symbol for a battery in a circuit?

What is the symbol for a switch in a circuit?

Cell terminals

Which is the positive terminal?

The one on the left.

What is the technique for remembering the positive and negative terminals on a cell?

You can draw a “P” on the big positive side.

Component symbols and their meanings

What is the symbol for a diode in a circuit?

What does this represent in a circuit?

A diode.

What is the symbol for a resistor in a circuit?

What does this represent in a circuit?

A resistor.

What is the symbol for a variable-resistor in a circuit?

What does this represent in a circuit?

A variable resistor.

What is the symbol for a fuse in a circuit?

What does this represent in a circuit?

A fuse.

What is the symbol for a voltmeter in a circuit?

What does this represent in a circuit?

A voltmeter.

What is the symbol for a ammeter in a circuit?

What does this represent in a circuit?

An ammeter.

What is the symbol for a thermistor in a circuit?

What does this represent in a circuit?

A thermistor.

What is the symbol for a led in a circuit?

What does this represent in a circuit?

An LED.

What is the symbol for a capacitor in a circuit?

What does this represent in a circuit?

A capacitor.

Connecting meters

Should you connect an ammeter in series or in parallel?

In series.

Should you connect a voltmeter in series or in parallel?

In parallel.

Diodes

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 $0.7V$.

How fuses work

How do fuses work?

They contain a wire which melts if the current is too high.