Sharing

Question 1

What impact do variable resistors have on a potential divider circuit?

Answer 1

• 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

Question 2

What happens when the second resistor has a larger resistance than the first resistor?

Answer 2

The voltage output between the two resistors will equal the voltage input.

Question 3

What happens when the second resistor has much less resistance than the first resistor?

Answer 3

The voltage output between the two resistors will equal 0.

Question 4

When will some electronic components start working at?

Answer 4

A threshold voltage, using a variable resistor as part of the potential divider allows the threshold voltage to be set.

Question 5

How is the resistance affected when resistors are arranged in parallel?

Answer 5

The overall resistance decreases.

1/Rt = 1/R1 + 1/R2 + 1/R3

Question 6

What happens in an LDR (light dependant resistor)?

Answer 6

As light intensity increases, resistance decreases.

Question 7

What happens in a thermistor?

Answer 7

As temperature increases, resistance decreases.

Question 8

What uses LDRs and thermistors?

Answer 8

• LDRs are in streetlights

- Thermistors are in heaters