LEDs

Question 1

What is the purpose of an LED?

Answer 1

Used to indicate whether there is a current in a circuit

Question 2

How does an LED work?

Answer 2

It emits light when a current flows through

Question 3

What happens when light increases in an LDR?

Answer 3

The resistance of the LDR decreases

Question 4

What does a thermistor do?

Answer 4

Changed resistance at different temperatures

Question 5

What happens when there’s a high temperature in a thermistor?

Answer 5

Resistance decreases

Question 6

What happens when there’s a low temperature in a themistor?

Answer 6

Resistance increases

Question 7

Why is a themistor different?

Answer 7

It’s a semi conductor

Question 8

What happens when the themistor heats in terms of electrons?

Answer 8

Releases more free charge carriers (electrons) to carry charge and transfer energy to lower resistance

Question 9

What is an LED?

Answer 9

A light emitting diode

Question 10

Why is an LED a more efficient source of light than a filament lamp?

Answer 10

LED wastes less energy than a filament lamp

Useful energy output/total energy input is larger for LED