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Created page with "==Key Stage 4== ===Meaning=== Investigate the factors affecting the resistance in a circuit. ===Experiment 1a: Resistance and Length of a Wire==..."
==Key Stage 4==
===Meaning===
Investigate the factors affecting the [[Electrical Resistance|resistance]] in a [[circuit]].
===Experiment 1a: Resistance and Length of a Wire===
====Variables====
: [[Independent Variable]]: The [[length]] of a [[wire]].
: [[Dependent Variable]]: The [[Electrical Resistance|resistance]] of the [[wire]].
: [[Control Variable]]s: The thickness of the [[wire]]. The [[temperature]] of the [[wire]]. The [[Electrical Current|current]] through the [[wire]].
====Method====
{| class="wikitable"
|-
|[[File:RequiredPracticalWireResistance2.png|center|600px]]
|-
| style="height:20px; width:200px; text-align:center;" |A [[Circuit Diagram|circuit diagram]] of the [[apparatus]] used to investigate the effect of the length of a [[wire]] on its [[Electrical Resistance|resistance]].
|}
: Set up the equipment as shown in the [[diagram]].
#Place the clips for the [[voltmeter]] at 5cm apart on the [[wire]].
#Close the [[switch]] and read and record the [[Electrical Current|current]] from the [[ammeter]].
#Read and record the [[Potential Difference|potential difference]] on the [[voltmeter]].
#Use the equation <math>V=IR</math> to calculate the [[Electrical Resistance|resistance]] of this length of [[wire]].
#Repeat steps 3 and 4 increasing the distance between the clips by an [[interval]] of 5cm a further 5 times.
#Plot a [[Scatter Graph|scatter graph]] with the length of [[wire]] on the [[x-axis]] and the [[Electrical Resistance|resistance]] on the [[y-axis]]. The [[gradient]] of [[Line of Best Fit|line of best fit]] will show the relationship between the length of the [[wire]] and its [[Electrical Resistance|resistance]].
====Improving [[Accuracy]]====
: Open the [[switch]] to stop the [[Electrical Current|current]] from [[heating]] the [[wire]] when [[results]] are not being [[read]]. This improves [[accuracy]] because [[Electrical Resistance|resistance]] is affected by the [[temperature]] of the [[wire]].
: Ensure a low [[Electrical Current|current]] throughout to reduce the [[heating]] effect of the [[Electrical Current|current]] on the [[wire]]. This improves [[accuracy]] because [[Electrical Resistance|resistance]] is affected by the [[temperature]] of the [[wire]].
====Improving [[Precision]]====
: Use an [[ammeter]] with a greater [[resolution]].
: Use a [[voltmeter]] with a greater [[resolution]].
===Experiment 1b: Resistance and Length of a Wire===
====Variables====
: [[Independent Variable]]: The [[length]] of a [[wire]].
: [[Dependent Variable]]: The [[Electrical Resistance|resistance]] of the [[wire]].
: [[Control Variable]]s: The thickness of the [[wire]]. The [[temperature]] of the [[wire]].
====Method====
{| class="wikitable"
|-
|[[File:RequiredPracticalWireResistance1.png|center|600px]]
|-
| style="height:20px; width:200px; text-align:center;" |A [[Circuit Diagram|circuit diagram]] of the [[apparatus]] used to investigate the effect of the length of a [[wire]] on its [[Electrical Resistance|resistance]].
|}
: Set up the equipment as shown in the [[diagram]].
#Close the [[switch]].
#Place the clips for the [[circuit]] at 10cm apart on the [[wire]].
#Close the [[switch]].
#Read and record the [[Potential Difference|potential difference]] on the [[voltmeter]] and the [[Electrical Current|current]] from the [[ammeter]].
#Use the equation <math>V=IR</math> to calculate the [[Electrical Resistance|resistance]] of this length of [[wire]].
#Repeat steps 4 and 5 increasing the distance between the clips by an [[interval]] of 10cm a further 5 times.
#Plot a [[Scatter Graph|scatter graph]] with the length of [[wire]] on the [[x-axis]] and the [[Electrical Resistance|resistance]] on the [[y-axis]]. The [[gradient]] of [[Line of Best Fit|line of best fit]] will show the relationship between the length of the [[wire]] and its [[Electrical Resistance|resistance]].
====Improving [[Accuracy]]====
: Open the [[switch]] to stop the [[Electrical Current|current]] from [[heating]] the [[wire]] when [[results]] are not being [[read]]. This improves [[accuracy]] because [[Electrical Resistance|resistance]] is affected by the [[temperature]] of the [[wire]].
: Ensure a low [[Electrical Current|current]] throughout to reduce the [[heating]] effect of the [[Electrical Current|current]] on the [[wire]]. This improves [[accuracy]] because [[Electrical Resistance|resistance]] is affected by the [[temperature]] of the [[wire]].
: Use larger lengths of [[wire]] and a greater [[interval]] to reduce the [[heating]] effect of the [[Electrical Current|current]] on the [[wire]] (since the [[Electrical Current|current]] will be lower for longer lengths of [[wire]]. This improves [[accuracy]] because [[Electrical Resistance|resistance]] is affected by the [[temperature]] of the [[wire]].
====Improving [[Precision]]====
: Use an [[ammeter]] with a greater [[resolution]].
: Use a [[voltmeter]] with a greater [[resolution]].
===Experiment 2: Resistors in Series===
====Variables====
: [[Independent Variable]]: The number of identical [[resistor]]s
: [[Dependent Variable]]: The [[Electrical Resistance|resistance]] of the [[circuit]].
: [[Control Variable]]s: The [[Electrical Resistance|resistance]] of the [[resistor]]s. The [[Potential Difference|potential difference]] across the [[resistor]]s. The [[temperature]] of the [[resistor]]s.
====Method====
{| class="wikitable"
|-
|[[File:RequiredPracticalSeriesResistor1.png|center|200px]]
|[[File:RequiredPracticalSeriesResistor2.png|center|200px]]
|[[File:RequiredPracticalSeriesResistor3.png|center|200px]]
|-
| style="height:20px; width:200px; text-align:center;" colspan = "3"|A [[Circuit Diagram|circuit diagram]] of the [[apparatus]] used to investigate the effect of the number of [[resistor]]s in [[Series Circuit|series]] and the [[Electrical Resistance|resistance]] in the [[circuit]].
|}
#Connect a [[Power Supply|power supply]] and an [[ammeter]] in [[Series Circuit|series]] with a [[resistor]].
#Connect a [[voltmeter]] in [[Parallel Circuit|parallel]] across the single [[resistor]].
#[[Read]] and record the [[Electrical Current|current]] from the [[ammeter]] and the [[Potential Difference|potential difference]] from the [[voltmeter]].
#Use the equation <math>V=IR</math> to calculate the [[Electrical Resistance|resistance]].
#Add an identical [[resistor]] in [[Series Circuit|series]] and connect the [[voltmeter]] in [[Parallel Circuit|parallel]] across both [[resistor]]s.
#Repeat steps 3-5 for as many [[resistor]]s as is available.
====Improving [[Accuracy]]====
: Open the [[switch]] to stop the [[Electrical Current|current]] from [[heating]] the [[resistor]]s when [[results]] are not being [[read]]. This improves [[accuracy]] because [[Electrical Resistance|resistance]] is affected by the [[temperature]] of the [[resistor]]s.
: Ensure a low [[Electrical Current|current]] throughout to reduce the [[heating]] effect of the [[Electrical Current|current]] on the [[resistor]]s. This improves [[accuracy]] because [[Electrical Resistance|resistance]] is affected by the [[temperature]] of the [[resistor]]s.
====Improving [[Precision]]====
: Use an [[ammeter]] with a greater [[resolution]].
: Use a [[voltmeter]] with a greater [[resolution]].
===Experiment 2: Resistors in Parallel===
====Variables====
: [[Independent Variable]]: The number of identical [[resistor]]s
: [[Dependent Variable]]: The [[Electrical Resistance|resistance]] of the [[circuit]].
: [[Control Variable]]s: The [[Electrical Resistance|resistance]] of the [[resistor]]s. The [[Potential Difference|potential difference]] across the [[resistor]]s. The [[temperature]] of the [[resistor]]s.
====Method====
{| class="wikitable"
|-
|[[File:RequiredPracticalParallelResistor1.png|center|200px]]
|[[File:RequiredPracticalParallelResistor2.png|center|200px]]
|[[File:RequiredPracticalParallelResistor3.png|center|200px]]
|-
| style="height:20px; width:200px; text-align:center;" colspan = "3"|A [[Circuit Diagram|circuit diagram]] of the [[apparatus]] used to investigate the effect of the number of [[resistor]]s in [[Series Circuit|series]] and the [[Electrical Resistance|resistance]] in the [[circuit]].
|}
#Connect a [[Power Supply|power supply]] and an [[ammeter]] in [[Series Circuit|series]] with a [[resistor]].
#Connect a [[voltmeter]] in [[Parallel Circuit|parallel]] across the single [[resistor]].
#[[Read]] and record the [[Electrical Current|current]] from the [[ammeter]] and the [[Potential Difference|potential difference]] from the [[voltmeter]].
#Use the equation <math>V=IR</math> to calculate the [[Electrical Resistance|resistance]].
#Add an identical [[resistor]] in [[Parallel Circuit|parallel]] and connect the [[voltmeter]] in [[Parallel Circuit|parallel]] across both [[resistor]]s.
#Repeat steps 3-5 for as many [[resistor]]s as is available.
====Improving [[Accuracy]]====
: Open the [[switch]] to stop the [[Electrical Current|current]] from [[heating]] the [[resistor]]s when [[results]] are not being [[read]]. This improves [[accuracy]] because [[Electrical Resistance|resistance]] is affected by the [[temperature]] of the [[resistor]]s.
: Ensure a low [[Electrical Current|current]] throughout to reduce the [[heating]] effect of the [[Electrical Current|current]] on the [[resistor]]s. This improves [[accuracy]] because [[Electrical Resistance|resistance]] is affected by the [[temperature]] of the [[resistor]]s.
====Improving [[Precision]]====
: Use an [[ammeter]] with a greater [[resolution]].
: Use a [[voltmeter]] with a greater [[resolution]].
===Meaning===
Investigate the factors affecting the [[Electrical Resistance|resistance]] in a [[circuit]].
===Experiment 1a: Resistance and Length of a Wire===
====Variables====
: [[Independent Variable]]: The [[length]] of a [[wire]].
: [[Dependent Variable]]: The [[Electrical Resistance|resistance]] of the [[wire]].
: [[Control Variable]]s: The thickness of the [[wire]]. The [[temperature]] of the [[wire]]. The [[Electrical Current|current]] through the [[wire]].
====Method====
{| class="wikitable"
|-
|[[File:RequiredPracticalWireResistance2.png|center|600px]]
|-
| style="height:20px; width:200px; text-align:center;" |A [[Circuit Diagram|circuit diagram]] of the [[apparatus]] used to investigate the effect of the length of a [[wire]] on its [[Electrical Resistance|resistance]].
|}
: Set up the equipment as shown in the [[diagram]].
#Place the clips for the [[voltmeter]] at 5cm apart on the [[wire]].
#Close the [[switch]] and read and record the [[Electrical Current|current]] from the [[ammeter]].
#Read and record the [[Potential Difference|potential difference]] on the [[voltmeter]].
#Use the equation <math>V=IR</math> to calculate the [[Electrical Resistance|resistance]] of this length of [[wire]].
#Repeat steps 3 and 4 increasing the distance between the clips by an [[interval]] of 5cm a further 5 times.
#Plot a [[Scatter Graph|scatter graph]] with the length of [[wire]] on the [[x-axis]] and the [[Electrical Resistance|resistance]] on the [[y-axis]]. The [[gradient]] of [[Line of Best Fit|line of best fit]] will show the relationship between the length of the [[wire]] and its [[Electrical Resistance|resistance]].
====Improving [[Accuracy]]====
: Open the [[switch]] to stop the [[Electrical Current|current]] from [[heating]] the [[wire]] when [[results]] are not being [[read]]. This improves [[accuracy]] because [[Electrical Resistance|resistance]] is affected by the [[temperature]] of the [[wire]].
: Ensure a low [[Electrical Current|current]] throughout to reduce the [[heating]] effect of the [[Electrical Current|current]] on the [[wire]]. This improves [[accuracy]] because [[Electrical Resistance|resistance]] is affected by the [[temperature]] of the [[wire]].
====Improving [[Precision]]====
: Use an [[ammeter]] with a greater [[resolution]].
: Use a [[voltmeter]] with a greater [[resolution]].
===Experiment 1b: Resistance and Length of a Wire===
====Variables====
: [[Independent Variable]]: The [[length]] of a [[wire]].
: [[Dependent Variable]]: The [[Electrical Resistance|resistance]] of the [[wire]].
: [[Control Variable]]s: The thickness of the [[wire]]. The [[temperature]] of the [[wire]].
====Method====
{| class="wikitable"
|-
|[[File:RequiredPracticalWireResistance1.png|center|600px]]
|-
| style="height:20px; width:200px; text-align:center;" |A [[Circuit Diagram|circuit diagram]] of the [[apparatus]] used to investigate the effect of the length of a [[wire]] on its [[Electrical Resistance|resistance]].
|}
: Set up the equipment as shown in the [[diagram]].
#Close the [[switch]].
#Place the clips for the [[circuit]] at 10cm apart on the [[wire]].
#Close the [[switch]].
#Read and record the [[Potential Difference|potential difference]] on the [[voltmeter]] and the [[Electrical Current|current]] from the [[ammeter]].
#Use the equation <math>V=IR</math> to calculate the [[Electrical Resistance|resistance]] of this length of [[wire]].
#Repeat steps 4 and 5 increasing the distance between the clips by an [[interval]] of 10cm a further 5 times.
#Plot a [[Scatter Graph|scatter graph]] with the length of [[wire]] on the [[x-axis]] and the [[Electrical Resistance|resistance]] on the [[y-axis]]. The [[gradient]] of [[Line of Best Fit|line of best fit]] will show the relationship between the length of the [[wire]] and its [[Electrical Resistance|resistance]].
====Improving [[Accuracy]]====
: Open the [[switch]] to stop the [[Electrical Current|current]] from [[heating]] the [[wire]] when [[results]] are not being [[read]]. This improves [[accuracy]] because [[Electrical Resistance|resistance]] is affected by the [[temperature]] of the [[wire]].
: Ensure a low [[Electrical Current|current]] throughout to reduce the [[heating]] effect of the [[Electrical Current|current]] on the [[wire]]. This improves [[accuracy]] because [[Electrical Resistance|resistance]] is affected by the [[temperature]] of the [[wire]].
: Use larger lengths of [[wire]] and a greater [[interval]] to reduce the [[heating]] effect of the [[Electrical Current|current]] on the [[wire]] (since the [[Electrical Current|current]] will be lower for longer lengths of [[wire]]. This improves [[accuracy]] because [[Electrical Resistance|resistance]] is affected by the [[temperature]] of the [[wire]].
====Improving [[Precision]]====
: Use an [[ammeter]] with a greater [[resolution]].
: Use a [[voltmeter]] with a greater [[resolution]].
===Experiment 2: Resistors in Series===
====Variables====
: [[Independent Variable]]: The number of identical [[resistor]]s
: [[Dependent Variable]]: The [[Electrical Resistance|resistance]] of the [[circuit]].
: [[Control Variable]]s: The [[Electrical Resistance|resistance]] of the [[resistor]]s. The [[Potential Difference|potential difference]] across the [[resistor]]s. The [[temperature]] of the [[resistor]]s.
====Method====
{| class="wikitable"
|-
|[[File:RequiredPracticalSeriesResistor1.png|center|200px]]
|[[File:RequiredPracticalSeriesResistor2.png|center|200px]]
|[[File:RequiredPracticalSeriesResistor3.png|center|200px]]
|-
| style="height:20px; width:200px; text-align:center;" colspan = "3"|A [[Circuit Diagram|circuit diagram]] of the [[apparatus]] used to investigate the effect of the number of [[resistor]]s in [[Series Circuit|series]] and the [[Electrical Resistance|resistance]] in the [[circuit]].
|}
#Connect a [[Power Supply|power supply]] and an [[ammeter]] in [[Series Circuit|series]] with a [[resistor]].
#Connect a [[voltmeter]] in [[Parallel Circuit|parallel]] across the single [[resistor]].
#[[Read]] and record the [[Electrical Current|current]] from the [[ammeter]] and the [[Potential Difference|potential difference]] from the [[voltmeter]].
#Use the equation <math>V=IR</math> to calculate the [[Electrical Resistance|resistance]].
#Add an identical [[resistor]] in [[Series Circuit|series]] and connect the [[voltmeter]] in [[Parallel Circuit|parallel]] across both [[resistor]]s.
#Repeat steps 3-5 for as many [[resistor]]s as is available.
====Improving [[Accuracy]]====
: Open the [[switch]] to stop the [[Electrical Current|current]] from [[heating]] the [[resistor]]s when [[results]] are not being [[read]]. This improves [[accuracy]] because [[Electrical Resistance|resistance]] is affected by the [[temperature]] of the [[resistor]]s.
: Ensure a low [[Electrical Current|current]] throughout to reduce the [[heating]] effect of the [[Electrical Current|current]] on the [[resistor]]s. This improves [[accuracy]] because [[Electrical Resistance|resistance]] is affected by the [[temperature]] of the [[resistor]]s.
====Improving [[Precision]]====
: Use an [[ammeter]] with a greater [[resolution]].
: Use a [[voltmeter]] with a greater [[resolution]].
===Experiment 2: Resistors in Parallel===
====Variables====
: [[Independent Variable]]: The number of identical [[resistor]]s
: [[Dependent Variable]]: The [[Electrical Resistance|resistance]] of the [[circuit]].
: [[Control Variable]]s: The [[Electrical Resistance|resistance]] of the [[resistor]]s. The [[Potential Difference|potential difference]] across the [[resistor]]s. The [[temperature]] of the [[resistor]]s.
====Method====
{| class="wikitable"
|-
|[[File:RequiredPracticalParallelResistor1.png|center|200px]]
|[[File:RequiredPracticalParallelResistor2.png|center|200px]]
|[[File:RequiredPracticalParallelResistor3.png|center|200px]]
|-
| style="height:20px; width:200px; text-align:center;" colspan = "3"|A [[Circuit Diagram|circuit diagram]] of the [[apparatus]] used to investigate the effect of the number of [[resistor]]s in [[Series Circuit|series]] and the [[Electrical Resistance|resistance]] in the [[circuit]].
|}
#Connect a [[Power Supply|power supply]] and an [[ammeter]] in [[Series Circuit|series]] with a [[resistor]].
#Connect a [[voltmeter]] in [[Parallel Circuit|parallel]] across the single [[resistor]].
#[[Read]] and record the [[Electrical Current|current]] from the [[ammeter]] and the [[Potential Difference|potential difference]] from the [[voltmeter]].
#Use the equation <math>V=IR</math> to calculate the [[Electrical Resistance|resistance]].
#Add an identical [[resistor]] in [[Parallel Circuit|parallel]] and connect the [[voltmeter]] in [[Parallel Circuit|parallel]] across both [[resistor]]s.
#Repeat steps 3-5 for as many [[resistor]]s as is available.
====Improving [[Accuracy]]====
: Open the [[switch]] to stop the [[Electrical Current|current]] from [[heating]] the [[resistor]]s when [[results]] are not being [[read]]. This improves [[accuracy]] because [[Electrical Resistance|resistance]] is affected by the [[temperature]] of the [[resistor]]s.
: Ensure a low [[Electrical Current|current]] throughout to reduce the [[heating]] effect of the [[Electrical Current|current]] on the [[resistor]]s. This improves [[accuracy]] because [[Electrical Resistance|resistance]] is affected by the [[temperature]] of the [[resistor]]s.
====Improving [[Precision]]====
: Use an [[ammeter]] with a greater [[resolution]].
: Use a [[voltmeter]] with a greater [[resolution]].