# Worksheet: Using Potential Dividers

In this worksheet, we will practice finding the output voltage of a potential divider and describing how potential dividers can be used in sensing circuits.

Q1:

What type of electronic component could be used instead of one of the resistors in a potential divider to create a light-sensing circuit?

• AA fuse
• BA light-dependent resistor
• CA thermistor
• DA diode
• EAn LED

Q2:

Chloe creates the potential divider shown in the diagram. has a value of 30 Ω, and has a value of 90 Ω. What ratio of output voltage to input voltage does this produce? Q3:

Isabella has a light bulb that requires a 12 V potential difference across it in order to work. She only has an 18 V battery to power it. Which of the following pairs of resistors can be used to create a potential divider to power the light bulb?

• A200 Ω and 500 Ω
• B8 kΩ and 6 kΩ
• C12 kΩ and 2 kΩ
• D48 Ω and 36 Ω
• E10 kΩ and 5 kΩ

Q4:

A potential divider has an input voltage of 48 V. The resistance of the second resistor, , is 100 kΩ. The output voltage is drawn across the second resistor, . What resistance must the first resistor, , have in order to produce an output voltage of 32 V?

Q5:

A potential divider has an input voltage of 36 V. The resistance of the first resistor, , is 48 Ω. The output voltage is drawn across the second resistor, . What resistance must the second resistor have in order to produce an output voltage of 18 V?

Q6:

A potential divider consists of two resistors, and . The resistance of is 200 Ω, and the resistance of is 400 Ω. The output voltage is drawn across . What input voltage is needed to produce an output voltage of 12 V?

Q7:

The diagram shows a circuit for a potential divider. The value of is 24 kΩ. The value of is 32 kΩ. What input voltage is needed to produce an output voltage of 8 V? Q8:

The diagram shows a circuit for a potential divider. If the input voltage, , is 30 V, what value of is needed to produce an output voltage of 20 V? Q9:

A potential divider has an input voltage of 24 V. The resistance of the first resistor, , is 25 Ω. The resistance of the second resistor, , is 75 Ω. The output voltage is drawn across the second resistor. What is the value of the output voltage?

Q10:

The diagram shows a circuit for a potential divider. If the input voltage is 12 V, what value of is needed to produce an output voltage of 4 V? Q11:

The diagram shows a circuit for a potential divider. If the input voltage, , is equal to 15 V, what is the value of the output voltage, ? Q12:

The diagram shows a circuit for a potential divider consisting of a thermistor and a variable resistor. This circuit can be used as a temperature sensor. The input voltage, , is 12 V. The variable resistor is set to a resistance of 10 kΩ. At a temperature of , the thermistor has a resistance of 50 kΩ. What is the value of the output voltage when the temperature is ?

• A6 V
• B2.4 V
• C2 V
• D9.6 V
• E10 V

The variable resistor is kept at a resistance of 10 kΩ. At a temperature of , the thermistor has a resistance of 500 kΩ. What is the value of the output voltage when the temperature is ? Give your answer to 2 decimal places.

• A0.6 V
• B12 V
• C11.43 V
• D11.4 V
• E0.57 V

In order for the output voltage to register as a value of 1 in the logic circuit that it is connected to, it must be at least 98% of the value of the input voltage. What is the lowest value of resistance that the variable resistor can be set to in order to achieve this output voltage at ? Give your answer in kilohms.

• A24 kΩ
• B30 kΩ
• C0.51 kΩ
• D0.49 kΩ
• E24.5 kΩ

Q13:

The diagram shows a circuit for a potential divider that consists of a resistor and a thermistor. This potential divider could be used as part of a temperature-sensing circuit. The resistance of the thermistor decreases as the temperature increases.

As the temperature of the thermistor increases, the output voltage . As the temperature of the thermistor decreases, the output voltage . • Aincreases, decreases
• Bincreases, stays the same
• Cdecreases, decreases
• Ddecreases, increases
• Eincreases, increases