P2: Quiz 9 – Answers

1) total resistance = potential difference ÷ current, or R = V ÷ I

2)

a) Increases

b) Decreases

3)

a)

2)

a) Increases

b) Decreases

3)

a)

*You can use a cell or battery.**Also, you can have a voltmeter around the cell/ battery.*b) Create a circuit with 1 resistor and take a reading for the current from the ammeter; the ammeter can be placed anywhere on the circuit. We can work out the total resistance by dividing the potential difference of the battery (source PD) by the current on the ammeter.

We then add another identical resistor in series and find the total resistance in the circuit by dividing the source PD by the current on the ammeter.

We keep adding more resistors in series and repeat the process of finding total resistance until we have around 6-8 identical resistors in the circuit.

c)

We then add another identical resistor in series and find the total resistance in the circuit by dividing the source PD by the current on the ammeter.

We keep adding more resistors in series and repeat the process of finding total resistance until we have around 6-8 identical resistors in the circuit.

c)

*A straight-line graph like what is shown below.*4)

a)

*You can use a cell or battery.*

*Also, you can have a voltmeter around the cell/ battery.*

b) Create a circuit with 1 resistor and take a reading for the current from the ammeter. We can work out the total resistance by dividing the potential difference of the battery (source PD) by the current on the ammeter.

We then add another identical resistor in parallel and find the total resistance in the circuit by dividing the source PD by the current on the ammeter.

We keep adding more identical resistors in parallel and repeat the process until we have around 6-8 identical resistors in the circuit.

c)

We then add another identical resistor in parallel and find the total resistance in the circuit by dividing the source PD by the current on the ammeter.

We keep adding more identical resistors in parallel and repeat the process until we have around 6-8 identical resistors in the circuit.

c)

*A curved graph like what is shown below.***Questions**

1) What is the calculation for finding total resistance in a circuit?

2)

a) For series circuits, does adding more identical resistors increase or decrease the total resistance in the circuit?

b) For parallel circuits, does adding more identical resistors increase or decrease the total resistance in the circuit?

3) This question is about investigating how the total resistance in a series circuit changes with the number of identical resistors.

a) Draw a diagram of the circuit that we would use to measure the total resistance in a series circuit for 2 identical resistors.

b) Explain how we can investigate how the total resistance in a series circuit is affected by the number of identical resistors.

c) On the graph below, draw how the total resistance in a series circuit changes with the number of identical resistors.

4) This question is about investigating how the total resistance in a parallel circuit changes with the number of identical resistors.

a) Draw a diagram of the circuit that we would use to measure the total resistance in a parallel circuit for 2 identical resistors.

b) Explain how we can investigate how the total resistance in a parallel circuit is affected by the number of identical resistors.

c) On the graph below, draw how the total resistance in a parallel circuit changes with the number of identical resistors.