Chapter 9.9 - The LDR Flashcards
1
Q
What is a light-dependent resistor (LDR)
A
Semiconductor with resistance decreases as light intensity increases
2
Q
How does an LDR work
A
- In dark conditions the LDR has a very high resistance (often MΩ)
- number density of free electrons is very low
- When light intensity increases number density of charge carriers increases (dramatically)
- Rapid decrease of resistance
3
Q
What does a graph of resistance against light intensity look like (for an LDR)
A
