Flashcard 1
Q → What is the overall aim of the required practical on reflection and refraction?
A → The aim of the experiment is to investigate the reflection of light by different types of surface and the refraction of light by different substances. This includes investigating light reflecting off smooth and rough surfaces, and investigating how light is refracted when it passes through transparent materials such as glass, acrylic polymer, and other substances.
Flashcard 2
Q → Why must both reflection and refraction experiments be carried out in a dim room?
A → Both experiments use rays of light, so they should be carried out in a dim room so that the light rays can be clearly seen. A dim environment makes it easier to trace the light rays accurately and measure angles precisely.
Flashcard 3
Q → Why are a ray box or laser used in these experiments?
A → A ray box or a laser is used to produce thin, narrow rays of light. Thin rays make it easier to see the middle of the ray when tracing it and allow more accurate measurement of angles using a protractor.
Flashcard 4
Q → What is the law of reflection?
A → The law of reflection states that the angle of incidence is equal to the angle of reflection. This relationship should always be observed when light reflects from a surface.
Flashcard 5
Q → Define the key terms: incident ray, angle of incidence, reflected ray, and angle of reflection.
A → The incident ray is the incoming ray of light that strikes a surface. The angle of incidence is the angle between the incident ray and the normal (a line drawn at 90° to the surface). The reflected ray is the ray that bounces off the surface. The angle of reflection is the angle between the reflected ray and the normal.
Flashcard 6
Q → What is refraction?
A → Refraction is the bending of light as it passes from one medium to another, such as from air into a glass block. This bending occurs at the boundary between different substances.
Flashcard 7
Q → Define the key terms: angle of refraction, normal, and optical density.
A → The angle of refraction is the angle between the refracted ray and the normal. The normal is a line drawn at 90 degrees to the surface at the point where the ray strikes. Optical density refers to how much a material slows down light; materials with different optical densities refract light by different amounts.
Reflection Practical (Mirror and Surfaces)
Flashcard 8
Q → What apparatus is required to investigate the reflection of light from a smooth surface such as a mirror?
A → The apparatus includes:
A ray box (light source)
A flat mirror
A protractor
A ruler
A pencil
Paper
Flashcard 9
Q → Describe how to set up the paper for the reflection experiment using a mirror.
A → Place a piece of paper on the table. Using a ruler, draw a straight solid line in the middle of the paper. Then use a protractor to draw a dotted line at 90° to this line so that it bisects it. This 90° line represents the normal to the mirror’s surface.
Flashcard 10
Q → How is the mirror positioned in the reflection experiment?
A → The mirror is positioned along the solid line drawn on the paper, aligned carefully with the markings so that its surface sits directly on the line.
Flashcard 11
Q → How is the light ray directed in the reflection experiment?
A → Switch on the ray box and aim a beam of light towards the point where the solid line and the normal line intersect. This point should be at the edge of the mirror.
Flashcard 12
Q → How are the paths of the incident and reflected rays marked in the mirror experiment?
A → Mark the position of the light beam just after it exits the ray box. Also mark the position where it reflects off the mirror. After turning off the ray box and removing the mirror, use a ruler to join these marked positions back to the point where the drawn lines intersect.
Flashcard 13
Q → How are the angles measured in the mirror reflection experiment?
A → Use a protractor to measure the angles between each ray and the normal (the 90° line). The angle between the incoming ray and the normal is the angle of incidence. The angle between the reflected ray and the normal is the angle of reflection.
Flashcard 14
Q → Why must the reflection experiment be repeated at different angles?
A → The procedure should be repeated several times with the beam aimed at different angles to ensure reliability of the results. Repeating measurements improves confidence in the conclusion.
Flashcard 15
Q → What should the results of the mirror reflection experiment show?
A → The results should show that the angle of incidence equals the angle of reflection, confirming the law of reflection.
Reflection from Different Materials
Flashcard 16
Q → How do you investigate reflection from different types of surfaces?
A → Draw a straight line across a piece of paper and place an object so one of its sides lines up with the line. Shine a ray of light at the object’s surface and trace both the incoming and reflected rays.
Flashcard 17
Q → How are angles measured when investigating reflection from different materials?
A → Draw the normal at the point where the ray hits the object. Use a protractor to measure the angle of incidence and the angle of reflection. Record these values in a table.
Flashcard 18
Q → What additional observations should be recorded when investigating reflection from different surfaces?
A → You should record the width and brightness of the reflected light ray. This helps compare how different materials reflect light.
Flashcard 19
Q → What is observed when light reflects from smooth surfaces compared to rough surfaces?
A → Smooth surfaces, such as mirrors, produce clear reflections where the reflected ray is as thin and bright as the incident ray. Rough surfaces, such as paper, cause diffuse reflection. This makes the reflected beam wider and dimmer, or sometimes not clearly observable at all.
Flashcard 20
Q → What conclusion should always be found regarding angles during reflection?
A → The angle of incidence always equals the angle of reflection, regardless of the type of surface.
Refraction Practical (Glass and Polymer Blocks)
Flashcard 21
Q → What apparatus is required to investigate refraction through a glass block?
A → The apparatus includes:
A glass block
A ray box or optical pins
Plain paper
A pencil
A protractor
A ruler
Flashcard 22
Q → How do you prepare the glass or rectangular block for a refraction experiment?
A → Place the transparent rectangular block on a piece of paper and trace around it to outline its shape. Ensure it does not move while tracing.
Flashcard 23
Q → How is the incident ray produced in the refraction experiment?
A → Set up a ray box, slit and lens so that a narrow ray of light is produced. Shine the ray at the middle of one side of the block, where the normal meets the block.
Flashcard 24
Q → How are the paths of light marked in the refraction experiment?
A → Mark the incident ray with a cross. Mark the reflected ray with a cross. Mark the ray that leaves the block with two crosses — one near the block and one further away. Also mark the point of incidence (where the ray enters) and the point of emergence (where the ray exits). After removing the block, join the crosses to show the full path of the light rays.
Flashcard 25
Q → How are the normals drawn in the refraction experiment?
A → Draw a normal line (a line at 90° to the surface) at the point where the light ray enters the block and at the point where it exits. The normal is used as a reference to measure angles.
Flashcard 26
Q → How are the angles of incidence and refraction measured?
A → Use a protractor to measure the angle between the incident ray and the normal (angle of incidence, I), and the angle between the refracted ray and the normal (angle of refraction, R).
Flashcard 27
Q → How should the angle of incidence be varied in the refraction investigation?
A → Adjust the angle of incidence in 10-degree intervals, starting from 10° up to 70°. For each angle, repeat the marking and measuring steps.
Flashcard 28
Q → How can different materials be used to investigate refraction?
A → Repeat the experiment using rectangular blocks made from different materials, such as acrylic polymer and glass, keeping the incident angle the same. The boundaries between different substances refract light by different amounts.
Flashcard 29
Q → What should be recorded in the results table for refraction experiments?
A → Record the angle of incidence, angle of refraction, and angle of reflection for each block (polymer and glass) in a suitable results table.
Flashcard 30
Q → How should the results of the refraction experiment be analysed?
A → Compare the angle of incidence with the angle of reflection for each block. Compare the angle of incidence with the angle of refraction for each block. Analyse how the angle of refraction changes as the angle of incidence increases.
Flashcard 31
Q → What pattern should be observed between angle of incidence and angle of refraction?
A → As the angle of incidence increases, the angle of refraction changes. Additionally, different materials produce different angles of refraction due to their different optical densities.
Evaluation and Risk Assessment
Flashcard 32
Q → To what extent should the results support the law of reflection?
A → The light rays should obey the law of reflection, meaning the angle of incidence should equal the angle of reflection. The results should be evaluated to determine how closely they match this expected relationship.
Flashcard 33
Q → What are the risks associated with using a ray box?
A → The ray box can become hot, which may cause minor burns. You should not touch the bulb and should allow time for it to cool down after use.
Flashcard 34
Q → What safety consideration is needed when performing the experiment in a dim room?
A → A semi-dark environment increases the risk of tripping. Therefore, you must ensure the area is clear of potential trip hazards before lowering the lights.
Source 1: Required Practical: Reflection and Refraction:
1. Reflection of Light:
This experiment investigates light reflecting off a smooth surface such as a mirror, and aims to demonstrate the LAW OF REFLECTION, which states that the ANGLE OF INCIDENCE = ANGLE OF REFLECTION. Apparatus:
Ray box (light source)
Flat mirror
Protractor
Ruler
Pencil
Paper
Method:
Place a piece of paper on the table.
Using a RULER, draw a straight solid LINE in the middle of the paper.
Use a PROTRACTOR to draw a dotted line at a 90° angle that bisects the line. This line serves as the NORMAL to the mirror’s surface.
Position the mirror along the solid line, aligning it with the markings on the paper.
Switch on a RAY BOX and aim a beam of light towards the point where the two lines cross, which should be at the edge of the mirror.
Mark the position of the light beam just after it exits the ray box and the position where it REFLECTS off the mirror.
After turning off the ray box and removing the mirror, use a ruler to join these two marked positions back to the point where the drawn lines intersect. Use the PROTRACTOR to measure the angles relative to the normal (90° line). The angle of the incoming ray is the ANGLE OF INCIDENCE, and the angle of the reflected ray is the ANGLE OF REFLECTION.
REPEAT the procedure several times with the beam of light aimed at different angles to ensure reliability of the results.
The results should show that the ANGLE OF INCIDENCE = ANGLE OF REFLECTION.
- Refraction of Light
This experiment demonstrates REFRACTION - the bending of light as it passes through a GLASS BLOCK.
The aim is to investigate how the angle of INCIDENCE affects the angle of REFRACTION.
Apparatus:
Glass block
Ray box or optical pins
Plain paper
Pencil
Protractor
Ruler
Method:
Place the glass block on a piece of paper and draw around it to outline its shape.
Position the RAY BOX so that it shines a light ray through the glass block at an initial angle of incidence.
Mark the point where the light ray enters the glass block (point of incidence).
Mark the point where the light ray exits the glass block (point of emergence).
Draw straight lines from the ray box to the point of incidence and from the point of emergence outward.
Draw a NORMAL LINE (a line at 90 degrees) to the surface at the point where the light enters and exits the block.
Use a PROTRACTOR to measure the angle of incidence (the angle between the incoming ray and the normal) and the angle of refraction (the angle between the refracted ray and the normal).
Adjust the angle of incidence in 10-degree intervals, starting from 10 degrees up to 70 degrees.
For each setting, REPEAT the marking and measuring steps. Analyse how the angle of refraction changes with varying angles of incidence.
You will find that as the ANGLE OF INCIDENCE INCREASES, the ANGLE OF REFRACTION CHANGES. ////////// Source 2: Required practical:
Investigate the reflection of light by different types of surface and the refraction of light by different substances:
Aim of the experiment:
To investigate the reflection of light by different types of surface, and the refraction of light by different substances.
Method: Set up a ray box, slit and lens so that a narrow ray of light is produced.
Place a 30 centimetre (cm) ruler near the middle of a piece of plain A3 paper. Draw a straight line parallel to its longer sides. Use a protractor to draw a second line at right angles to this line. Label this line with an ‘N’ for ‘normal’.
Place the longest side of a rectangular acrylic polymer block against the first line. With the normal near the middle of the block, carefully draw around the block without moving it.
Use the ray box to shine a ray of light at the point where the normal meets the block. This is the
incident ray
.
The angle between the normal and the incident ray is called the angle of incidence. Move the ray box or paper to change the angle of incidence. The aim is to see a clear ray reflected from the surface of the block and another clear ray leaving the opposite face of the block.
Using a pencil on the paper, mark the path of:
- the incident ray with a cross
- the reflected ray with a cross
- the ray that leaves the block with two crosses - one near the block and the other further away
Remove the block. Join the crosses to show the paths of the light rays.
Repeat steps 2 to 7 for a rectangular glass block.
Measure the angle of incidence, angle of refraction and angle of reflection for each block.
Results:
Record results in a suitable table, for both the polymer block and the glass block. ||| Analysis:
- compare the angle of incidence with the angle of reflection for each block
- compare the angle of incidence with the angle of refraction for each block
Evaluation:
The light rays should obey the law of reflection. To what extent do the results show this?
Risks/hazards: A ray box getting hot can lead to minor burns, so you should not touch the bulb and allow time for it to cool.
A semi-dark environment results in an increased trip hazard, therefore you must ensure the environment is clear of potential trip hazards before lowering the lights. ////////// Source 3: INVESTIGATING LIGHT: You Need to Do Both of These Experiments in a Dim Room:
Both experiments use rays of light, so it’s best to do them in a dim room so you can clearly
see the light rays. They also both use either a ray box or a laser to produce thin rays of light.
This is so you can easily see the middle of the ray when tracing it and measuring angles from it.
You Can Use Transparent Materials to Investigate Refraction: The boundaries between different substances refract light by different amounts. You can investigate this by looking at how much light is refracted when it passes from air into different materials: 1) Place a transparent rectangular block on a piece of paper
and trace around it. Use a ray box or a laser to shine a ray
of light at the middle of one side of the block.
2) Trace the incident ray and mark where the light ray emerges
oh the other side of the block. Remove the block and, with
a straight line, join up the incident ray and the emerging point to
show the path of the refracted ray through the block.
3) Draw the hormal at the point where the light ray entered the block.
Use a protractor to measure the angle between the incident ray and
the hormal (the angle of incidence, I) and the angle between the
refracted ray and the normal (the angle of refraction, R).
4) Repeat this experiment using rectangular blocks made from different
materials, keeping the incident angle the same throughout.
You should find that the angle of refraction changes for different materials
- this difference is due to their different optical densities. ||| Different Materials Reflect Light by Different Amounts:
1) Take a piece of paper and draw a straight line across it.
Place an object so ohe of its sides lines up with this line.
2) Shine a ray of light at the object’s surface
and trace the incoming and reflected light beams.
3) Draw the hormal at the point where the ray hits the object.
Use a protractor to measure the angle of incidence
and the angle of reflection and record these values
in a table. Also make a hote of the width and
brightness of the reflected light ray.
4) Repeat this experiment for a range of objects.
You should also see that smooth surfaces like mirrors give clear reflections (the reflected ray
is as thin and bright as the incident ray). Rough surfaces like paper cause diffuse reflection which causes the reflected beam to be wider and dimmer (or hot observable at all).
You should also find that the angle of incidence ALWAYS equals the angle of reflection.
Flashcard 1
Q → What is the overall aim of the required practical on reflection and refraction?
A → The aim of the experiment is to investigate the reflection of light by different types of surface and the refraction of light by different substances. This includes investigating light reflecting off smooth and rough surfaces
and investigating how light is refracted when it passes through transparent materials such as glass
Flashcard 2
Q → Why must both reflection and refraction experiments be carried out in a dim room?
A → Both experiments use rays of light
so they should be carried out in a dim room so that the light rays can be clearly seen. A dim environment makes it easier to trace the light rays accurately and measure angles precisely.
Flashcard 3
Q → Why are a ray box or laser used in these experiments?
A → A ray box or a laser is used to produce thin
narrow rays of light. Thin rays make it easier to see the middle of the ray when tracing it and allow more accurate measurement of angles using a protractor.
Flashcard 4
Q → What is the law of reflection?
A → The law of reflection states that the angle of incidence is equal to the angle of reflection. This relationship should always be observed when light reflects from a surface.
Flashcard 5
Q → Define the key terms: incident ray
angle of incidence
A → The incident ray is the incoming ray of light that strikes a surface. The angle of incidence is the angle between the incident ray and the normal (a line drawn at 90° to the surface). The reflected ray is the ray that bounces off the surface. The angle of reflection is the angle between the reflected ray and the normal.
Flashcard 6
Q → What is refraction?
A → Refraction is the bending of light as it passes from one medium to another
such as from air into a glass block. This bending occurs at the boundary between different substances.
Flashcard 7
Q → Define the key terms: angle of refraction
normal
A → The angle of refraction is the angle between the refracted ray and the normal. The normal is a line drawn at 90 degrees to the surface at the point where the ray strikes. Optical density refers to how much a material slows down light; materials with different optical densities refract light by different amounts.
Reflection Practical (Mirror and Surfaces)
Flashcard 8
-
Energy Stores and Transfers, Open and Closed Systems36
-
Examples of Energy Transfers, Energy Flow Diagrams13
-
Calculation of Energy Changes, Conservation of Energy11
-
Energy Dissipation, Reducing Unwated Energy Transfers in the Home13
-
Conduction and Convection112
-
Specific Heat Capacity, Intro to Thermal Conductivity22
-
Required Practical: Specific Heat Capacity20
-
Power124
-
Required Practical: Investigating Insulation121
-
Efficiency108
-
Types of Energy Resources290
-
Trends and Uses of Energy Resources, Energy for Transport and Heating246
-
Charge and Current82
-
Current, Potential Difference & Resistance58
-
Required Practical: Investigating Resistance89
-
Resistors and I-V Graphs132
-
Required Practical: I-V Graphs99
-
Series and Parallel Circuits55
-
Direct and Alternating Current31
-
Mains Electricity78
-
Electrical Power25
-
Electrical Energy Transfers and Power Ratings71
-
The National Grid84
-
Static Electricity and Sparks77
-
Electric Fields and Sparks75
-
Density - Intro13
-
Required Practical: Density17
-
States of Matter36
-
Internal Energy35
-
Specific Latent Heat, Heating & Cooling Graphs (and recap of Internal Energy)36
-
Particle Motion in Gases, Gas Pressure & Temp, Boyle's Law, Work Done on Gases41
-
Atomic Structure, Radioactive Decay, Types of Radiation, Intro to G-M Tube75
-
Nuclear Equations, Half Life, Contamination, Irradiation, Peer Reviewing79
-
Background Radiation, Correct Count-Rate, Uses and Risks of Radiation45
-
Nuclear Fission and Fusion97
-
Scalars and Vectors24
-
Contact and Non-Contact Forces71
-
Gravity, Weight & Centre of Mass97
-
Resultant Forces, Scale Drawings, & Components of a Force113
-
Work Done and Its Energy Transfers53
-
Forces and Elasticity112
-
Required Practical: Force and Extension118
-
Moments, Levers and Gears101
-
Pressure in Fluids118
-
Upthrust and Atmospheric Pressure67
-
Distance and Displacement17
-
Speed and Velocity25
-
Distance-Time Graphs24
-
Acceleration106
-
Velocity-Time Graphs61
-
Terminal Velocity121
-
Newton's First Law and Inertia61
-
Newton's Second Law and Inertial Mass51
-
Newton's Third Law73
-
Required Practical: Force, Mass and Acceleration137
-
Stopping Distance and How Braking Works131
-
Momentum and Changes in Momentum104
-
Vehicle Safety Features40
-
Transverse & Longitudinal Waves36
-
Wave Period & Speed, Measuring the Speed of Sound in Air23
-
Required Practical: Measuring Waves in a Ripple Tank19
-
Required Practical: Measuring Waves on a String9
-
Sound Waves and Human Hearing101
-
Using Ultrasound for Imaging and Detection70
-
Using Seismic Waves for Exploration81
-
Intro to Electromagnetic Waves, Intro to Visible Light92
-
Uses of Radio Waves91
-
Uses of Microwaves25
-
Uses of Infrared Radiation33
-
Uses of Visible Light21
-
Uses of Ultraviolet Radiation25
-
Uses of X-Rays and Gamma Rays27
-
Dangers of Electromagnetic Waves63
-
Visible Light and Colour Filters137
-
Required Practical: Investigating Infrared Radiation75
-
Reflection and Refraction114
-
Specular and Diffuse Reflection61
-
Required Practical: Reflection and Refraction119
-
Lenses and Ray Diagrams153
-
Black Body Radiation and Earth’s Temperature169
-
Magnetism and Types of Magnets28
-
Magnetic Fields30
-
Electromagnetism, The Right Hand Grip Rule and Solenoids40
-
The Motor Effect55
-
Fleming's Left Hand Rule41
-
Electric Motors and Loudspeakers25
-
Induced Potential, The Generator Effect and Microphones52
-
Transformers and their Equations137
-
Our Solar System and Orbital Motion184
-
The Life Cycle of Stars100
-
Red Shift and The Big Bang81
