View source for GCSE Physics Required Practical: Investigating Reflection and Refraction of Light

==Key Stage 4==
===Meaning===
Investigate the [[Specular Reflection|reflection]] and [[refraction]] of [[light]].

===Experiment 1: Reflection from a Plane Mirror===
====Method====
{| class="wikitable"
|-
|[[File:RequiredPracticalReflection1.png|center|300px]]
|[[File:RequiredPracticalReflection2.png|center|300px]]
|-
| style="height:20px; width:200px; text-align:center;" colspan = "2"|A pair of [[diagram]]s of the [[apparatus]] used to investigate the [[Specular Reflection|reflection]] of [[light]].
|}

#Place a [[Plane Mirror|plane mirror]] in the centre of a piece of paper and draw a pencil line along its reflective side.
#Use a [[Ray Box|ray box]] and a slit to allow a single beam of [[light]] to be [[Incident Ray|incident]] on the surface of the [[Plane Mirror|mirror]] at an [[angle]] less than 90°.
#Place a pair of x's on the [[Incident Ray|incident ray]] and along the [[Reflected Ray|reflected ray]].
#Remove the [[Ray Box|ray box]] and [[Plane Mirror|mirror]].
#Use a [[ruler]] to join the x's with a pair of lines leading to the [[Plane Mirror|mirror]] to show the direction of the [[Incident Ray|incident]] and [[Reflected Ray|reflected]] rays.
#Use a [[protractor]] and [[ruler]] to draw a [[Normal Line|normal line]] at [[Right Angle|right angles]] to the surface of the [[Plane Mirror|mirror]] at the point the [[Light Ray|light ray]]s meet the [[Plane Mirror|mirror]].
#Use the [[protractor]] to [[measure]] the 'i' the [[Angle of Incidence|angle of incidence]] and 'r' the [[Angle of Reflection|angle of reflection]].
#Repeat this procedure for a number of different [[Angle of Incidence|angles of incidence]].

====Improving [[Accuracy]]====
: Drawing the [[Light Ray|rays]] longer and using a larger [[protractor]] may reduce the [[error]] in [[reading]] the [[protractor]] and improve [[accuracy]].

====Improving [[Precision]]====
: Drawing the [[Light Ray|rays]] longer and using a larger [[protractor]] with a better [[resolution]] will improve [[precision]].

===Experiment 2: Refraction from a Rectangular Glass Block===
====Method====
{| class="wikitable"
|-
|[[File:RequiredPracticalRefraction1.png|center|300px]]
|[[File:RequiredPracticalRefraction2.png|center|300px]]
|-
| style="height:20px; width:200px; text-align:center;" colspan = "2"|A pair of [[diagram]]s of the [[apparatus]] used to investigate the [[refraction]] of [[light]].
|}

#Place a rectangular glass block in the centre of a piece of paper and draw a pencil line around the outside.
#Use a [[Ray Box|ray box]] and a slit to allow a single beam of [[light]] to be [[Incident Ray|incident]] on the surface of the glass block at an [[angle]] less than 90°.
#Place a pair of x's on the [[Incident Ray|incident ray]] and along the [[Emergent Ray|emergent ray]].
#Remove the [[Ray Box|ray box]] and glass block.
#Use a [[ruler]] to join the x's with a pair of lines leading to the glass block to show the direction of the [[Incident Ray|incident]] and [[Emergent Ray|emergent]] rays.
#Join the [[Emergent Ray|emergent ray]] and the [[Incident Ray|incident ray]] with a line to represent the [[Refracted Ray|refracted ray]].
#Use a [[protractor]] and [[ruler]] to draw a [[Normal Line|normal line]] at [[Right Angle|right angles]] to the surface of the glass block at the point the [[Light Ray|light ray]]s meet the glass block.
#Use the [[protractor]] to [[measure]] the 'i' the [[Angle of Incidence|angle of incidence]] and 'r' the [[Angle of Refraction|angle of refraction]].
#Repeat this procedure for a number of different [[Angle of Incidence|angles of incidence]].

====Improving [[Accuracy]]====
: Drawing the [[Light Ray|rays]] longer and using a larger [[protractor]] may reduce the [[error]] in [[reading]] the [[protractor]] and improve [[accuracy]].

====Improving [[Precision]]====
: Drawing the [[Light Ray|rays]] longer and using a larger [[protractor]] with a better [[resolution]] will improve [[precision]].