GCSE Physics Required Practical: Investigating Electrical Components - Revision history

NRJC: /* Method */

2020-11-20T13:42:23Z

‎Method

NRJC: /* Improving Precision */

2019-10-17T08:28:36Z

‎Improving Precision

NRJC: /* Improving Precision */

2019-10-17T08:28:15Z

‎Improving Precision

NRJC: /* Improving Precision */

2019-10-17T08:27:59Z

‎Improving Precision

NRJC: /* Improving Precision */

2019-10-17T08:27:46Z

‎Improving Precision

NRJC: /* Improving Precision */

2019-10-17T08:27:33Z

‎Improving Precision

NRJC at 11:35, 13 April 2019

2019-04-13T11:35:57Z

NRJC: Created page with "==Key Stage 4== ===Meaning=== Investigate the I-V characteristics of electrical components. ===Experiment 1a: Resistor=== ====Variables=..."

2019-03-20T15:06:59Z

Created page with "==Key Stage 4== ===Meaning=== Investigate the I-V characteristics of electrical components. ===Experiment 1a: Resistor=== ====Variables=..."

New page

==Key Stage 4==
===Meaning===
Investigate the [[IV Graph|I-V characteristics]] of [[Electrical Component|electrical components]].

===Experiment 1a: Resistor===
====Variables====
: [[Independent Variable]]: The [[Potential Difference|potential difference]] across the [[resistor]].
: [[Dependent Variable]]: The [[Electrical Current|current]] through the [[resistor]]

====Method====
{| class="wikitable"
|-
|[[File:ResistorIVGraphCircuit.png|center|300px]]
| style="height:20px; width:300px; text-align:left;" |
#Connect an [[ammeter]] in [[Series Circuit|series]] with the [[resistor]] to measure [[Electrical Current|current]] through the [[resistor]].
#Connect a [[voltmeter]] in [[Parallel Circuit|parallel]] with the [[resistor]] to measure the [[Potential Difference|potential difference]] across it.
#Use a [[Variable Resistor|variable resistor]] in [[Series Circuit|series]] with the [[resistor]] to vary the [[Potential Difference|potential difference]] across the [[resistor]].
#Start with a [[Potential Difference|potential difference]] of zero and increase the [[Potential Difference|potential difference]] by an interval of 0.2V up to 2V.
#Recording the [[reading]]s on the [[voltmeter]] and [[ammeter]].
#Reverse the connections on the [[battery]] and repeat steps 4 and 5 to find the [[IV Graph|I-V relationship]] for negative [[Potential Difference|potential difference]] and [[Electrical Current|current]].
|}

====Improving [[Precision]]====
: Use an [[ammeter]] with a greater [[resolution]].
: Use a [[voltmeter]] with a greater [[resolution]].

====Results====
{| class="wikitable"
|-
|[[File:IVGraphResistor.png|center|400px]]
|}

====Conclusion====
====Description====
The [[IV Graph]] for a [[resistor]] shows that:
*As [[Potential Difference|potential difference]] increases, [[Electrical Current|increases]].
*The relationship between [[Potential Difference|potential difference]] and [[Electrical Current|current]] is [[linear]] (the [[gradient]] is constant).
*The [[Electrical Current|current]] is [[Directly Proportional|directly proportional]] to [[Potential Difference|potential difference]].

=====Explanation=====
: [[Resistor]]s obey [[Ohm's Law]] so the "[[Electrical Current|current]] through a [[Electrical Resistor|resistor]] at constant [[temperature]] is [[Directly Proportional|directly proportional]] to the [[Potential Difference|potential difference]] across the [[resistor]]."

===Experiment 1b: Filament Bulb===
====Variables====
: [[Independent Variable]]: The [[Potential Difference|potential difference]] across the [[Electrical Bulb|bulb]].
: [[Dependent Variable]]: The [[Electrical Current|current]] through the [[Electrical Bulb|bulb]]

====Method====
{| class="wikitable"
|-
|[[File:BulbIVGraphCircuit.png|center|300px]]
| style="height:20px; width:300px; text-align:left;" |
#Connect an [[ammeter]] in [[Series Circuit|series]] with the '''bulb''' to measure [[Electrical Current|current]] through the '''bulb'''.
#Connect a [[voltmeter]] in [[Parallel Circuit|parallel]] with the '''bulb''' to measure the [[Potential Difference|potential difference]] across it.
#Use a [[Variable Resistor|variable resistor]] in [[Series Circuit|series]] with the '''bulb''' to vary the [[Potential Difference|potential difference]] across the '''bulb'''.
#Start with a [[Potential Difference|potential difference]] of zero and increase the [[Potential Difference|potential difference]] by an interval of 1V up to 10V.
#Recording the reading on the [[voltmeter]] and [[ammeter]].
#Reverse the connections on the [[battery]] and repeat steps 4 and 5 to find the I-V relationship for negative [[Potential Difference|potential difference]] and [[Electrical Current|current]].
|}

====Improving [[Precision]]====
: Use an [[ammeter]] with a greater [[resolution]].
: Use a [[voltmeter]] with a greater [[resolution]].

====Results====
{| class="wikitable"
|-
|[[File:IVGraphBulb.png|center|400px]]
|}

====Conclusion====
=====Description=====
The [[IV Graph]] for a '''bulb''' shows that:
*As [[Potential Difference|potential difference]] increases, [[Electrical Current|increases]].
*At small [[Potential Difference|potential differences]]] the the relationship between [[Potential Difference|potential difference]] and [[Electrical Current|current]] is [[linear]] (the [[gradient]] is constant).
*At large [[Potential Difference|potential differences]] the [[gradient]] becomes more shallow as the [[Electrical Resistance|resistance]] of the '''bulb''' increases.

=====Explanation=====
: At small [[Potential Difference|potential differences]] there is a small [[Electrical Current|current]] so the [[heating]] effect of the [[Electrical Current|current]] is small and the [[filament]] remains at a low [[temperature]].
: At large [[Potential Difference|potential differences]] there is a large [[Electrical Current|electrical current]] so the [[heating]] effect of the [[Electrical Current|current]] is large which causes the [[filament]] to be a high [[temperature]].
:: This is caused by [[electron]]s in the [[wire]] [[collide|colliding]] with [[ion]]s in the [[metal]] [[lattice]] causing them to [[vibrate]].
: [[Wire]]s (like the [[filament]]) have a greater [[Electrical Resistance|resistance]] at higher [[temperature]]s, causing the increase in [[Electrical Current|current]] to be reduced.
:: This is because the more the [[ion]]s in the [[metal]] [[lattice]] [[vibrate]] the more likely [[electron]]s are to [[collide]] with them and slow down.

===Experiment 1c: Diode or LED===
====Variables====
: [[Independent Variable]]: The [[Potential Difference|potential difference]] across the [[diode]].
: [[Dependent Variable]]: The [[Electrical Current|current]] through the [[diode]]

====Method====
{| class="wikitable"
|-
|[[File:DiodeIVGraphCircuit.png|center|300px]]
| style="height:20px; width:300px; text-align:left;" |
#Connect an [[ammeter]] in [[Series Circuit|series]] with the [[diode]] to measure [[Electrical Current|current]] through the [[diode]].
#Connect a [[voltmeter]] in [[Parallel Circuit|parallel]] with the [[diode]] to measure the [[Potential Difference|potential difference]] across it.
#Use a [[Variable Resistor|variable resistor]] in [[Series Circuit|series]] with the [[diode]] to vary the [[Potential Difference|potential difference]] across the [[diode]].
#Start with a [[Potential Difference|potential difference]] of zero and increase the [[Potential Difference|potential difference]] by an interval of 0.2V up to 2V.
#Recording the reading on the [[voltmeter]] and [[ammeter]].
#Reverse the connections on the [[battery]] and repeat steps 4 and 5 to find the I-V relationship for negative [[Potential Difference|potential difference]] and [[Electrical Current|current]].
|}

====Improving [[Precision]]====
: Use an [[ammeter]] with a greater [[resolution]].
: Use a [[voltmeter]] with a greater [[resolution]].

====Results====
{| class="wikitable"
|[[File:IVGraphDiode.png|center|400px]]
|}

====Conclusion====
=====Description=====
The [[IV Graph]] for a [[diode]] shows that:
*For a positive [[Potential Difference|potential difference]] the [[Electrical Current|current]] increases rapidly with an increase in [[Potential Difference|potential difference]]
*For a negative [[Potential Difference|potential difference]] the [[Electrical Current|current]] remains negligible and does not increase as the [[Potential Difference|potential difference]] becomes larger.

=====Explanation=====
: The [[Electrical Resistance|resistance]] of a [[diode]] is very low for [[Electrical Current|current]] in the forward direction and very high in the back direction.

===Experiment 1d: 'NTC' Thermistor===
====Variables====
: [[Independent Variable]]: The [[Potential Difference|potential difference]] across the [[thermistor]].
: [[Dependent Variable]]: The [[Electrical Current|current]] through the [[thermistor]]

====Method====
{| class="wikitable"
|-
|[[File:ThermistorIVGraphCircuit.png|center|300px]]
| style="height:20px; width:300px; text-align:left;" |
#Connect an [[ammeter]] in [[Series Circuit|series]] with the [[thermistor]] to measure [[Electrical Current|current]] through the [[thermistor]].
#Connect a [[voltmeter]] in [[Parallel Circuit|parallel]] with the [[thermistor]] to measure the [[Potential Difference|potential difference]] across it.
#Use a [[Variable Resistor|variable resistor]] in [[Series Circuit|series]] with the [[thermistor]] to vary the [[Potential Difference|potential difference]] across the [[thermistor]].
#Place the [[thermistor]] in a [[beaker]] of cold [[water]] around 5°C.
#Start with a [[Potential Difference|potential difference]] of zero and increase the [[Potential Difference|potential difference]] by an interval of 0.2V up to 2V.
#Recording the reading on the [[voltmeter]] and [[ammeter]].
#Reverse the connections on the [[battery]] and repeat steps 4 and 5 to find the I-V relationship for negative [[Potential Difference|potential difference]] and [[Electrical Current|current]].
#Repeat steps 5-7 with the [[thermistor]] in a [[beaker]] of hot [[water]] around 40°C.
|}

====Improving [[Precision]]====
: Use an [[ammeter]] with a greater [[resolution]].
: Use a [[voltmeter]] with a greater [[resolution]].

====Results====
{| class="wikitable"
|[[File:IVGraphThermistor.png|center|400px]]
|}

====Conclusion====
=====Description=====
The [[IV Graph]] for an 'NTC' [[thermistor]] shows that:
*At a high [[temperature]] the [[Electrical Current|current]] increases rapidly with the [[Potential Difference|potential difference]]
*At a low [[temperature]] the [[Electrical Current|current]] increases slowly with the [[Potential Difference|potential difference]].

=====Explanation=====
: The [[Electrical Resistance|resistance]] of an 'NTC' [[thermistor]] increases as the [[temperature]] decreases.

===Experiment 1a: Resistor===
====Variables====
: [[Independent Variable]]: The [[Potential Difference|potential difference]] across the [[Light Dependent Resistor|light dependent resistor]].
: [[Dependent Variable]]: The [[Electrical Current|current]] through the [[Light Dependent Resistor|light dependent resistor]]

====Method====
{| class="wikitable"
|-
|[[File:LDRIVGraphCircuit.png|center|300px]]
| style="height:20px; width:300px; text-align:left;" |
#Connect an [[ammeter]] in [[Series Circuit|series]] with the '''LDR''' to measure [[Electrical Current|current]] through the '''LDR'''.
#Connect a [[voltmeter]] in [[Parallel Circuit|parallel]] with the '''LDR''' to measure the [[Potential Difference|potential difference]] across it.
#Use a [[Variable Resistor|variable resistor]] in [[Series Circuit|series]] with the '''LDR''' to vary the [[Potential Difference|potential difference]] across the '''LDR'''.
#Cover the '''LDR''' so that very little light reaches its surface.
#Start with a [[Potential Difference|potential difference]] of zero and increase the [[Potential Difference|potential difference]] by an interval of 0.2V up to 2V.
#Recording the reading on the [[voltmeter]] and [[ammeter]].
#Reverse the connections on the [[battery]] and repeat steps 4 and 5 to find the I-V relationship for negative [[Potential Difference|potential difference]] and [[Electrical Current|current]].
#Repeat steps 5-7 while shining a constant bright [[light]] on the '''LDR'''
|}

====Improving [[Precision]]====
: Use an [[ammeter]] with a greater [[resolution]].
: Use a [[voltmeter]] with a greater [[resolution]].

====Results====
{| class="wikitable"
|[[File:IVGraphLDR.png|center|400px]]
|}

====Conclusion====
=====Description=====
The [[IV Graph]] for a [[Light Dependent Resistor|light dependent resistor]] shows that:
*At a high [[light]] intensity the [[Electrical Current|current]] increases rapidly with the [[Potential Difference|potential difference]]
*At a low [[light]] intensity the [[Electrical Current|current]] increases slowly with the [[Potential Difference|potential difference]].

=====Explanation=====
: The [[Electrical Resistance|resistance]] of an '''LDR''' increases as the [[light]] intensity decreases.

@@ Line 129: / Line 129: @@
 |-
 |[[File:ThermistorIVGraphCircuit.png|center|300px]]
-| style="height:20px; width:300px; text-align:left;" |
+| style="height:20px; width:500px; text-align:left;" |
 #Connect an [[ammeter]] in [[Series Circuit|series]] with the [[thermistor]] to measure [[Electrical Current|current]] through the [[thermistor]].
 #Connect a [[voltmeter]] in [[Parallel Circuit|parallel]] with the [[thermistor]] to measure the [[Potential Difference|potential difference]] across it.
@@ Line 139: / Line 139: @@
 #Repeat steps 5-7 with the [[thermistor]] in a [[beaker]] of hot [[water]] around 40°C.
 |}
 ====Improving [[Precision]]====

@@ Line 180: / Line 180: @@
 ====Improving [[Precision]]====
-: Use an [[ammeter]] with a greater [[resolution]].
+: Use the same component for each repeat. Do not just use the same value of component as they may be slightly different from one another.
-: Use a [[voltmeter]] with a greater [[resolution]].
+: Use a low [[Electrical Current|current]] and turn the circuit off between readings. This prevents the wires and components increasing in temperature which would increase resistance and affect future readings including repeat readings.
 ====Results====

@@ Line 1: / Line 1: @@
 ==Key Stage 4==
 ===Meaning===
 Investigate the [[IV Graph|I-V characteristics]] of [[Electrical Component|electrical components]].