DC Circuits 6

​Watch this video (3 mins)

​Make sure to understand:

• What is a potential divider circuit?

• ​What does it do?

Multiple Choice

Which one is true about potential dividers?

• It consists one fixed resistor

• It's resistors are connected in parallel to the power supply

• It's resistors connected in series to the power supply

• It's resistors connected in series and parallel to the power supply

​Watch this video (4 mins)

​Make sure to understand:

• ​How to calculate the voltage output of a potential divider circuit.

Multiple Choice

The V_out across the resistor of resistance R₁ is given by:

• $$V_{out\ }=\frac{R_{1\ }}{R_{1\ }+R_2}\times EMF$$  

• $$V_{out\ }=R_{2\ }\times\left(R_1+R_2\right)\times EMF$$

• $$V_{out\ }=R_{1\ }\times\left(R_1+R_2\right)\times EMF$$

• $$V_{out\ }=\frac{R_{2\ }}{R_{1\ }+R_2}\times EMF$$

Multiple Choice

A potential divider is set up with resistances as shown. Calculate the potential across the 100 Ω resistor.

• 48 V

• 192 V

• 96,000 V

• 240 V

Multiple Choice

A potential divider is set up with resistances as shown. Calculate the potential across the 400 Ω resistor.

• 48 V

• 192 V

• 96,000 V

• 240 V

Fill in the Blank

Two resistors are connected in series in a potential divider circuit with a battery that supplies 30 V. Resistor X produces an output voltage of 6 V. Calculate the resistance of resistor X.

(When entering your answer, you do not need to give the units)

​Watch this video (3 mins)

​Make sure to understand:

• ​How to calculate the voltage output of a potential divider circuit with variable resistor added.

Multiple Choice

When the resistor is set to 40 Ω, what is its V_out?

• 2 V

• 6 V

• 8 V

• 10 V

Multiple Choice

The picture shows a potential divider circuit with a fixed resistor and a variable resistor connected in series. The 20 Ω resistor is set as the tapped resistor. Calculate the maximum voltage output across the tapped resistor.

• 5 V

• 0.9 V

• 201 V

• 2001 V

Multiple Choice

The picture shows a potential divider circuit with a fixed resistor and a variable resistor connected in series. The 20 Ω resistor is set as the tapped resistor. Calculate the minimum voltage output across the tapped resistor.

• 5 V

• 0.9 V

• 201 V

• 2001 V

Open Ended

For the circuit in the diagram, state and explain what happens to the current in the circuit as you increase the resistance of the variable resistor from 20 Ω to 200 Ω?

Multiple Choice

Resistors X and Y are connected in series with a 6.0 V battery of negligible internal resistance.

X has resistance R and Y has resistance R/2.

A voltmeter of resistance R is connected across Y.

What is the reading on the voltmeter?

• 0.0 V

• 1.5 V

• 3.0 V

• 4.5 V