What impact do variable resistors have on a potential divider circuit?
- Fixed resistors the output voltage is a fixed proportion of the supply voltage
- If it has a variable resistor the output voltage can be altered
What happens when the second resistor has a larger resistance than the first resistor?
The voltage output between the two resistors will equal the voltage input.
What happens when the second resistor has much less resistance than the first resistor?
The voltage output between the two resistors will equal 0.
When will some electronic components start working at?
A threshold voltage, using a variable resistor as part of the potential divider allows the threshold voltage to be set.
How is the resistance affected when resistors are arranged in parallel?
The overall resistance decreases.
1/Rt = 1/R1 + 1/R2 + 1/R3
What happens in an LDR (light dependant resistor)?
As light intensity increases, resistance decreases.
What happens in a thermistor?
As temperature increases, resistance decreases.
What uses LDRs and thermistors?
- LDRs are in streetlights
- Thermistors are in heaters
