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Question 1

What are the properties of a potential divider circuit?

Answer 1

• Some potential divider circuit have fixed resistors.
• Some potential divider circuit have one variable resistor.
• The voltage can be altered.

Question 2

What is output voltage?

Answer 2

The output voltage is a fixed proportion of the of the supply voltage.

Question 3

V _out Eq.

Answer 3

Question 4

When R₂ is much larger than R₁

Answer 4

V _out ≈ V_in

Question 5

When R₂ is much less than R₁

Answer 5

V _out ≈ 0

Question 6

Threshold voltage

Answer 6

• Some electronic components will start working at a threshhold voltage.
• Using a variable resistor as one part of the potential divider allows the threshold voltage to be set.

Question 7

Resistors in parallel

Answer 7

Resistors can be arranged in parallel and this will decrease the total resistance.

Question 8

Eq. for resistors in parallel

Answer 8

Question 9

Resistance of light-dependent resistor

Answer 9

The resistance of a LDR decreases as the light intensity increases.

Question 10

Resistance of thermistor

Answer 10

The resistance of a thermistor decreases as the temperature increases.

Question 11

How are potential divider circuits used?

Answer 11

• Street lights have LDRs in potential divider circuit.
• When it is dark, the resistance of the LDR is high, the output voltage is high and switches on the street light.
• A thermistor can be used to switch on a heater when the temperature gets too low.