P2 - Diodes and LEDs

What is a diode?

A component that allows current to flow in one direction only

What is the symbol for a diode?

A triangle (arrow) pointing to a line, showing the direction current is allowed to flow

Why does current only flow one way through a diode?

Because the diode has very high resistance in the reverse direction

What happens if the current tries to flow in the reverse direction through a diode?

The diode blocks the current due to high resistance

Describe the current-potential difference (I-V) graph for a diode.

Current flows only in the forward direction and increases as potential difference increases; no current flows in the reverse direction

What is the practical use of diodes in circuits?

To control the direction of current flow

What is an LED?

A light emitting diode that allows current to flow in one direction and emits light when current flows

How does the symbol of an LED differ from a normal diode?

The LED symbol has arrows pointing away from it to represent light emission

Why are LEDs useful in everyday electronics?

They are energy-efficient light sources used in devices like cameras, light bulbs, and TVs

How does the current flow through an LED compare to a normal diode?

Both only allow current to flow in the forward direction

What happens when current flows through an LED?

The LED emits light

Why are LEDs more energy efficient than filament lamps?

Because they convert more electrical energy into light and less into heat

Where might you commonly find LEDs?

In electronic gadgets, LED light bulbs, flashlights, and TV screens

What does a high resistance in reverse direction mean for a diode?

It prevents current from flowing backward through the circuit

How does the diode protect circuits?

By blocking current in the reverse direction and allowing current only forward

What does the forward direction mean in terms of diode current?

The direction that the diode symbol's arrow points to and allows current to flow

What is the key feature to learn about diodes for the AQA GCSE exam?

The diode only allows current in one direction and blocks it in the other, shown by its I-V graph