Diodes, LEDs, Thermistors and LDRs _ GCSE Physics

The video tutorial covers the basics of diodes, including their resistance properties and voltage measurement. It explains the function and benefits of light-emitting diodes (LEDs), highlighting their energy efficiency and longevity compared to filament bulbs. The tutorial also discusses thermistors, which are used as temperature sensors in devices like fire alarms, and how their resistance changes with temperature. Finally, it explains light-dependent resistors (LDRs) and their role in adjusting to light levels, with resistance decreasing as light intensity increases.

What is the ideal resistance of a diode in the forward direction?

• High

• Variable

• Zero

• Infinite

How does a light-emitting diode (LED) produce light?

• When current flows through it in the forward direction

• By absorbing light

• By heating up

• By reflecting light

Why are LEDs becoming more popular compared to conventional filament bulbs?

• They are easier to install

• They are brighter

• They use less energy and last longer

• They are cheaper

What happens to the resistance of a thermistor as temperature increases?

• It decreases

• It fluctuates

• It remains constant

• It increases

How does the resistance of a light-dependent resistor (LDR) change with light intensity?

• Increases with more light

• Decreases with more light

• Remains constant

• Fluctuates randomly