AQA GCSE Physics P14 Light Kerboodle Answers

P14.1 1 Reflection of light AQA GCSE Physics P14 light Kerboodle Answers: Page No. 203

1 a i The law of reflection states that the angle of incidence = the angle of reflection. So if the angle of reflection is 20 then the angle of incidence = 200. ii The angle between the incident ray and the reflected ray is 400, because the angle between incident ray and reflected ray = 200+200 = 400. b If the mirror is turned and the angle of incidence is increased to 21 then the angle between incident ray and reflected ray will become 420. a The path of the two rays shown from O after they have been reflected from the mirror is shown in the figure below– b ii Since R= infinity for a plane mirror, By using mirror formula hence, 1/v+1/u = 2/R So  1/v=-1/u v = -u. Hence proved that the image and objectbare at the same distance from the mirror.   Two plane mirrors are placed perpendicular to each other. b The angle between the final reflected ray and the incident ray is 1800. ii Normal N1 perpendicular to normal N2 =1800. Rays after reflection from two mutually perpendicular mirrors becomes anti parallel.   Hence it can be concluded that the angle A is always equal to 180 whatever may be the angle of incidence. a The specular and diffuse reflection can be distinguished as- Reflection from a smooth surface is called specular reflection because parallel light rays are reflected in a single direction.Parallel light rays reflected from a rough surface are scattered in different directions. If you polish a rough surface like a dusty table top to make it smooth, you might see a reflection in the surface. Reflection from a rough surface is called diffuse reflection because the tight is scattered in different directions.   b The image formed by a plane mirror is virtual, upright (the same way up as the object), and laterally inverted (back to front but not upside down). A virtual image is formed at a place where light rays appear to come from after they have been reflected (or refracted). It can’t be projected onto a screen like the movie images you see at a cinema. An image that can be seen on a screen is described as a real Image because it is formed by focusing light rays onto the screen. The aforesaid are the differences between the real and virtual image.

P14.2 Refraction of light AQA GCSE Physics P14 Light Kerboodle Answers: Page No. 205

When a light ray travels from air into glass, its speed changes at the boundary. a There is a Decrease in speed of ligjt waves when they cross the boundary. b If the angle of incidence is 0 then the angle of refraction is Less than zero. c  If angle of incidence is non-zero then the angle of refraction is smaller than angle of incidence.   A light ray from the bottom of a swimming pool refracts at the water surface. Its angle of incidence is 40 degrees and its angle of refraction is 75 degrees. a b  The swimming pool apoears to be shallower than it is really when viewed from above because the rays of light reaching you from the object at the bottom of the water do not come straight to you, as they would if there was no water between you and the object. The light travels straight as long as it is in the water, but if it emerges obliquely from the water into the air it is bent downward toward the surface. This bending is known as refraction, and it occurs whenever light passes from one transparent medium into another of different density – as, for example, from water to air, or from air to glass. The eyes do not take refraction into account, but judge the position of the object as if the light came in a straight line. 4  When white light passes through a transparent medium (like air) into another (like glass), its components are deflected the first time according to their colour, and once again when they reemerge (back into air, for example). This creates a spread of coloured light rays from red to violet, like the colours of the rainbow. So we observe these seven colors on the screen when a white light is placed in the path of a narrow beam of white light. This ordered separation of coloured rays is known as the “spectrum”. The spectrum of white light consists of six basic colours arranged in a specific order: red, orange, yellow, green, blue and violet.

P14.3Light and colour AQA GCSE Physics P14 Light Kerboodle Answers: Page No.207

1 Its front cover appears black in appearance of red light and a white title  has no pigments, so it reflects light of any wavelength, either partially or totally. The surface looks white in daylight because daylight is white light and the reflected light contain red color in presence of red light. 2 The dress appears to be black due to the mixing of color in a scene where there is a blue light. 3 When a white light is directed through the first filter then due to its red colour it absorbs white light it emit only red light and red light on passing through blue filter emit black light.

P14.4 Lenses AQA GCSE Physics P14 Light Kerboodle Answers: Page No. 209

1 a The differences between a real image and a virtual image can be understood as follows-
  1. a) A real imageis always inverted whereas a virtual imageis always erect.
  2. b) A real imageis formed when the rays of light after reflection or refraction actually meet at some point whereas a virtual imageis formed when the rays of light after reflection or refraction appear to meet at a point.
b Determine whether a real image or a virtual image is formed when: I a A real image is formed by a convex lens of a diatant object on a screen. ii a With the object nearer to the lens than the principal focus, a magnified image is formed. The image is a virtual image because it is formed where the rays appear to come from. In this situation, the convex lens is used as a magnifying glass. Iii  The image formed by concave lens is seen to be virtual, erect and highly diminished than the object when the lens in used to form an image of a distant object. 2 a When a postage stamp is inspecred using convex lens as a magnifying glass the image is a virtual image because it is formed where the rays appear to come from. b A convex lens forms a magnified image of a slide on a screen. i The image formed by convex lens is seen to be real,inverted and diminished. ii When the screen is moved away from the lens, the object is moved nearer to the lens toward its principal focus. c i In the magnification of the fiower, the image is a virtual image because it is formed where the rays appear to come from. In this situation, the lens acts as a magnifying glass. ii If the flower is close to the lens the light rays enter at a sharper angled. This results in the rays converging away from the lens. As the lens can only bend the light to a certain agree the image needs to be focused in order to form on the film. This is achieved by moving the lens away from the film. Similarly, if the lens is moved away from the flower the rays enter at a wider angle. This results in the rays being refracted at a sharper angle and the image forming closer to the lens. In this case the lens needs to be positioned closer to the film to get a focused image. 3 a The image of the bird in figure 6b is bigger than the object (Figure 6b), the magnification is greater than 1. b With the object at different distances beyond the principal focus of the lens, adjust the position of the screen until you see a clear image of the object on it. This is a real image because it can be formed on a screen. When the lens is moved further away from the bird and the card is moved to obtain a new clear image  , the image is formed at the principal focus of the lens. This is because the rays from any point on the object are almost parallel to each other when they reach the lens. If the object is moved nearer to the lens towards its principal focus, the screen must be moved further from the lens for you to see a clear image. The nearer the object is to the lens, the larger the image with the object nearer to the lens than the principal focus, a magnified image is formed. The image is a virtual image because it is formed where the rays appear to come from. In this situation, the lens acts as a magnifying glass.   4 The following experiment can be used to find the magnification prodiced by the convex lens depends on the distance. With the object at different distances beyond the principal focus of the lens, adjust .The position of the screen until you see a clear image of the object on it. This is a real image because it can be formed on a screen.
  • When the object is a long distance away, the image is formed at the principal focus of the lens. This is because the rays from any point on the object are almost parallel to each other when they reach the lens.
  • If the object is moved nearer to the lens towards its principal focus, the screen must be moved further from the lens for you to see a clear image. The nearer the object is to the lens, the larger the image.
With the object nearer to the lens than the principal focus, a magnified image is formed. The image is a virtual image because it is formed where the rays appear to come from. In this situation, the lens acts as a magnifying glass.

P14.5 Using lenses AQA GCSE Physics P14 Light Kerboodle Answers: Page No. 211

a 2 The image is real. ii The image formed is Diminished.  iii The image is Inverted. a ) A convex lens is used as a magnifying glass when the object is placed between the lens and its principal focus the image is formed on the same side of the lens as the object. The image is virtual, upright, and larger than the object. The image can be seen only by looking at it through the lens. This is how a magnifying glass works. b The image formed is virtual. ii The image formed is magnified. iii The image formed is Upright. c  Convex lens is not used as a magnifying glass because the image formed by a concave lens is always virtual, upright, and smaller than the object. 3 A convex lens produces a magnification of x2 when it is used to forma real image that is at a distance of 8.0cm from the object. a  Draw two arrows on the axis of your scale diagram, which are 8 cm apart, one twice as big as the other. Now draw a line from the top of the bigger arrow through the top of the smaller arrow. Where this meets the axis is the position of the lens (this should be 8cm on the other side?) so now complete the ray diagram by drawing a line parallel to the axis from the top of the small arrow to the lens, then to the focal point on the other side. Then extrapolate this back to the top of the large arrow. b If the object is moved gradually towards the focal point of the lens towards its principal focus, the screen must be moved further from the lens for you to see a clear image. The nearer the object is to the lens, the larger the image and the image is real. 4 a i  ii The image formed is Real , inverted and the magnification is 1 i.e image is of same size as the object. b  An application for the use of lens is- In a camera, a convex lens is used to produce a real image of an object on a film (or on an array of pixels for a digital camera). The position of the lens is adjusted to focus the image on the film.
  • For a distant object, the distance from the lens to the film must be equal to the focal length of the lens.
  • The nearer an object is to the lens, the bigger is the distance from the lens to the film.
 

Summary questions AQA GCSE Physics P14 Light Kerboodle Answers Page No. 212

1 a  i  Angle x is angle of incidence and Angle y is angle of reflection, x = y ii  two correctly reflected rays and normals shown each reflected ray at same angle to normal as incident ray image located by tracing two reflected rays back and labelled at correct position jji The distance from the image to the mirror is same as the distance of the object from the mirror. b An experiment to test the law of reflection using the ray box and the plane mirror can be described as follows- draw straight line XY on white paper and use protractor to draw ‘normal’ perpendicular to XY, place mirror exactly on XY and direct light at point P where normal intersects XY using ray box, adjust direction of light ray so angle of incidence ≈ 10°, mark direction of incident and reflected rays, remove mirror and use protractor to measure angles of incidence and reflection, repeat for different angles of incidence, record all results in table, results should show angle of incidence = angle of reflection 2 a The figure shows a light ray directed into a rectangular glass block, i both refractions correct rays before and after passing through block parallel to each other ii  The ray emerging from the block is exactly parallel to the incident ray because- change in direction at second refraction exactly equal and opposite to change at first refraction, emerging light parallel to incident light because opposite sides of block parallel b  first refraction towards normal, 2nd refraction away from normal 3 a  The difference between specular and diffuse reflection is as follows-
  1. specular reflection parallel light rays are reflected in a single direction
  2. diffuse reflection the light is scattered in different directions
bi Translunce material are the materials that allow light to pass through but scatters it, i.e. images are not seen. ii  Translucence is caused because the material has many internal boundaries that repeatedly change direction of light rays 4  a i The type of lens that is shown in this diagram is converging ii 2 construction rays correct image correct b The image is real, inverted and smaller than the object An application of the lens used in this way is camera. 5 a at least 2 construction rays correct image correct in correct position b  The image formed is real. c  The magnification produced by the lens is 1.7 6 a at least 2 construction rays correct and image correct b Determine whether the image is: i The image is virtual ii The image is upright 7 a at least 2 construction rays correct and image correct b Determine whether the image in a is: i The image is virtual ii The image is upright  

Practice questions AQA GCSE Physics P14 Light Kerboodle Answers Page No. 213

01.1  A red and blue rugby shirt hanging on the line appeears red and blue because the red part absorbs all colours except red and the blue part absorbs all colours except blue and therefore blue and red are reflected 01.2  Skirt and Shirt appear black and white because black absorbs all colours in the spectrum and white reflects all colours in the spectrum 01.3 transparent – clear glass translucent – frosted glass opaque – black glass 02.1  correct labels 02.2When the light is reflected from a smooth surface it is called specular reflection. When the light is reflectes from a rough surface it is called diffuse reflection. 03.1 2.The range of the angles of incidence used in the investigation is 5–90 degrees (accept 0–90 degrees) 03.2 One way of improving the investigation is to calculate the mean of the results and draw one line 03.3 The name of possible error is systematic error 03.4 The percentage of light reflected changes with the angle of incidence as the angle of incidence increases the % reflection increases but not at a constant rate 04 Figure3 shows a lens, the position of an object, and the position of the image. 04.1 The type of the lens shown is convex lens 04.2 The name of the points F shown on each side of the lens is focal point 04.3The image shown is inverted and real.

Disclaimer

Disclaimer: I have tried by level best to provide the answers and video explanations to the best of my knowledge. All the answers and notes are written by me and if there is any similarity in the content then it is purely coincidental. But this is not an alternative to the textbook. You should cover the specification or the textbook thoroughly. This is the quick revision to help you cover the gist of everything. In case you spot any errors then do let us know and we will rectify it. References: BBC Bitesize AQA GCSE Science Kerboodle textbook Wikipedia Wikimedia Commons Join Our Free Facebook Group : Get A* in GCSE and A LEVEL Science and Maths by Mahima Laroyia: https://www.facebook.com/groups/expertguidance.co.uk/ For Free Tips, advice and Maths and Science Help

This page contains the detailed and easy notes for AQA GCSE Physics Waves for revision and understanding Waves.



AQA GCSE Paper 2: Complete Revision Summary

WAVES

  • Transverse and Longitudnal Waves
  • Properties of Waves
  • Reflection of Waves
  • Refractions of Waves
  • Sound Waves
  • Ultrasound
  • Electromagnetic Waves
  • Lenses
  • BlackBody Radiation





 

TRANSVERSE AND LONGITUDNAL WAVES

Waves are oscillations or disturbance that transfer energy from one point to another.

TRANSVERSE AND LONGITUDNAL WAVES

TRANSVERSE

LONGITUDNAL




PROPERTIES OF WAVES

Wave Speed

It is the distance travelled
by the wave each second.

Crest
It is the height of the
wave.

Amplitude

It is the maximum displacement
of the wave from the mean
position.

In the example it is 5 m

Frequency

It is the number of waves
passing each second.
It is measured in Hertz (Hz)

F = 1/T  1/4

=0.25H3

Wavelength

The distance between
two consecutive crests
or trough.

Time Period

The time it takes for one
wave to travel.

In the example, one wave
is completed in 4 second.

Trough
It is the depth of the wave.

WAVE SPEED




REFLECTION

  • It is the line perpendicular
    to the surface where reflection
    occurs.
  • It is the ray incident
    on the surface.
  • Angle of incidence is the
    angle between the incident
    ray and the normal.
  • It is the ray which is
    reflected from the surface.
  • Angle of reflection is the angle
    between the reflected ray and
    the normal.

Reflection is the phenomenon of bouncing
off the wave when it hits a medium.
eq: Reflection of light wave when it hits a plain
mirror.

LAWS OF REFLECTION

a) Incident ray, reflected ray
and normal are in the same
plane.

b) The angle of incidence
is equal to the angle
of reflection.

GCSE_Waves_Notes (1)

Download now

IMAGE OF A PLANE MIRROR

  • It is a virtual image
  • Laterally Inverted
  • Upright
  • The same distance from the source.
REAL IMAGEVIRTUAL IMAGE
1. Image can be obtained on a screen.1. Image cannot be obtained on a screen
2. The rays actually meet where the image
is formed.		2. The rays happen to meet where
the image is formed.
eg Images of the cinema 

TYPES OF REFLECTION

REFRACTION

  • Bending of light as it travels from one medium to another.
  • Light bends because speed of light is different
    in different medium.
  • If the light is travelling from rarer to denser medium then
    it bends towards the normal. ∠r < ∠i
  • If the light is travelling from denser to rarer medium then
    it bends away from the normal.∠r > ∠i

The pencil appears to be
broken as the light is
refracted in water.

VISIBLE LIGHT

Visble light is a spectrum of 7 colours VIBGYOR

Each colour has its own freqency and wavelength.

The visible colour of the object will be the colour that is reflected by the object.

Opaque Object

Opaque objects
does not allow the
light to be transmitted
but absorb all
the light.

eg Book,

Translucent Object

These objects
allow some part
of the light to be
transmitted.

eg Plastic

Transparent Object

They allow the
light to be transmitted
through them
without any absorption

eq glass




SOUND WAVES

  • They are longitudnal Waves.
  • Sound does not travel through a medium.
  • Sound requires a medium to travel.
  • Sound wave is characterized by compression and
    rarefaction.
  • In sound waves, particles vibrate parallel
    to the direction of the wave.

The speed of the sound wave is 330m/s.

Human hearing range
20 Hz to 20,000 Hz

In Echo sounding, high frequency sound waves are sent to determine
the depth or find any object.

The time taken by the sound to come back is noted for the known speed
of sound.

S = vt/2

ULTRASOUND

It is the frequency of sound greater than 20,000 Hz.

ADVANTAGES

  • 1. They are non ionizing and
    harmless.
  • 2. They are partially reflected
    at the boundaries between
    different tissues, so they
    can scan even the soft tissues.

USES

1. Used in prenatal scanning.

2. Used to determine the depth of
the sea or the obstacle inside

3. Industrial Imaging .
4. Detecting flaws in metal castings.
water.




USES OF ULTRASOUND

ULTRASOUND SCANNER

Transducer sends ultrasound waves. It crosses
the body and reflected from the tissues. The Transducer
detects the waves reflected from the tissues and the
image is diplayed on the screen in the form of scans.

SONAR

  • Ultrasound waves are used to measure
    the depth of the sea or find the obstacle
    under water.
  • In SONAR, ultrasound is sent to determine
    the depth or find any object.
  • The time taken by the sound to come back is noted
    for the known speed
    of sound.

STRUCTURE OF THE EARTH

The crust and the upper mantle cracks and
forms the tectonic plate. The Tectonic
Plates causes Earthquake.

SEISMIC WAVES

  • Earthquake takes place
    when the rocks or the tectonic
    plates in the Earth’s Crust
    or the upper Mantle Moves
    due to forces inside the Earth.
  • Seismic Waves are the shock waves
    which originate when the forces inside
    the earth moves the rocks or
    the tecctonic plates. These waves travel
    through the Earth and also across its surface.
  • The Earthquake are detected by Seismometer.
  • The focus is the
    point from where
    the Earthquake
    originates.
  • Seismology is the study of
    Seismic Waves.
  • The nearest point on the surface of the
    focus is the epicenter.

SEISMIC WAVES

P-WaveS-Wave

·        They are longitudinal

·        They are faster than
other waves.

·        They can travel through
solids and liquids.

·        They can pass through
liquid outer core.

·        They are transverse

·        They are slower than other waves

·        They travel through
solids only

·        S-waves cannot pass
through the liquid
outercore.

  • Shadow Zones are the place
    where no P and S waves are detected.
  • S shadow zones where no S wave
    and only P waves are detected.

P and S Wave travel through the Mantle
changing directions with depth.

P waves refract at the boundary between mantle and outer core.

S waves being transfer do not travel through liquid outer core.

1. Liquid Outer core under the Mentle.

Shadow zones are detected as P waves refract twice.
Once while entering the core from the mantle
and leaving the core from the mantle. Since
the refraction is further away forming shadow
zones it suggests a liquid outer core under the mantle.

2. Solid Inner Core

Weak P waves in the shadow zones caused by the
refraction of P waves while crossing the boundary
between outer core and inner core.

Long (L-waves) travel the slowest.
They happen only in the Earth’s
crust and they cause more violent
movements.




ELECTROMAGNETIC SPECTRUM

  • It is the spectrum with all the
    electromagnetic waves arranged
    in the order of the increasing wavelength
    or frequency.
  • Electromagnetic waves are electric
    and magnetic disturbances that transfer
    energy (no matter)
    from one point to another.
  • All the electromagnetic waves travel
    with the speed of light-3 x10 8m/s
  • The frequency and the wavelength can
    be given by the formuale :- V = Fλ

ELECTROMAGNETIC SPECTRUM
MNEMONIC




GAMMA RAYS

SOURCE

Gamma rays are produced when
the radiactive substance emit
nuclear radiations.

PROPERTIES
  • They have the lowest wavelength.
  • They have highest frequency.
  • They travel with the speed of light.
USES

1. They are uses to disinfect food
and surgical equipment.

2. It is used to kill cancer cells. In
gamma treatment, the cobalt 60 is
used to direct the gamma radiation to
the cancer cells and kill it without
affecting the surrounding tissue.

DISADVANTAGES

1. Gamma Rays are highly ionizing.

2. Exposure to low dose of Gamma Rays can cause
gene mutation, DNA damage and even cancer.

3. Exposure to high dose of Gamma radiation
can caused killing of the cell.

X-RAYS

SOURCES

They are produced by stopping
high speed electrons.

PROPERTIES

1. They are electromagnetic wave which travels
with the speed of light.

2. They have wavelength greater
than Gamma Rays but smaller than
ultraviolet rays.

3. They have lower frequency than
Gamma Rays but greater than
ultraviolet rays.

4. Their wavelength is about the diameter
of the atom.

USES

1. Shorter wavelength X-rays are
used in X-ray therapy
to kill cancer cells without
destroying the healthy cells.

2. Longer wavelength X-rays are used
to photograph the internal structure
of the body.

DISADVANTAGES

1. X-Rays are highly ionizing
2. Exposure to a low dose of Gamma Rays can cause
gene mutation, DNA damage and even cancer.
3. Exposure to a high dose of Gamma radiation
can caused killing of the cell.

HOW X-RAYS WORK ?

  • X-rays are passed through the body.
  • The X-rays passes through the soft tissues but are
    absorbed by the bones and harder tissues.
  • The X-rays that pass through the softer areas reach
    the detector and appears to be black whereas the
    rays that are absorbed do not reach the detector
    and appears light in the image.
  • If any organs containing softer tissues needs to be
    photographed then patient is given a contrasting
    medium like Barium which becomes a good absorber
    of X-rays and helps the photography of that organ.
  • The detector contains the charged coupled device CCD
    which converts X-rays to light which then creates electronic
    signal which are used by the computer to make a digital
    image.

ULTRA VIOLET RAYS

SOURCE

1. They are produced from the Sun.
The Sun is the source of ultraviolet
rays.

PROPERTIES

1. They are electromagnetic wave which travels
with the speed of light.

2. They have wavelength greater
than X-Rays but smaller than
Violet light.

3. They have lower frequency than
X- Rays but greater than
violet light.

USES

They are uses as fluorescent markers
or fluorescent lamps which contains the
chemical which converts UV Light
to Visible Light.

DISADVANTAGES

1. They can cause sunburn and suntan

2. They can also lead to skin cancer.

3. They can also lead to blindness.

VISIBLE LIGHT

SOURCE

1. Sun and lamps emits light
2. It is the only part of the
specturm which is visible.

PROPERTIES

1. It is made up of 7 colours

2. VIOLET
INDIGO
BLUE
GREEN
YELLOW
ORANGE
RED
3. When the white light is passed
through the prism, it can give the
spectrum of colours.

USES
  • Light is used in a camera to take
    the picture.
  • Light is also used in Light Microscope
  • Light helps to see the object.
  • Light waves are also used in
    communication.
DISADVANTAGES

Too much exposure to visible light
can lead to cancer, blindness and
skin damage.

INFRA RED WAVES

SOURCE
  • All the hot objects like Kettle, Toaster,
    Radiator emits infrared radiation.
PROPERTIES

1. They are electromagnetic wave which
travels
with the speed of light.

2. They have wavelength greater
than visible light but smaller than
Microwaves.

3. They have a lower frequency than visible
light but greater than
microwaves.

USES

1. They are used in optical fibres
for communication.

2. They are used in remote
controls.

3. They are used as infrared
scanners to detect heat produced
by the body and unhealthy
tissues

4. Infrared cameras helps
to see objects in dark.

DISADVANTAGES

1. They can cause sunburn and suntan

2. They can also lead to skin cancer.

3. They can also lead to blindness.

MICROWAVES

 

The water in the food
absorb microwaves and
become heated and heats the
food preventing the microwave
from heating as it has no water.

SOURCE
  • They are emitted as Cosmic Microwave
    Background Radiation. Sun also emits
    some microwaves.
PROPERTIES

1. They are electromagnetic wave which
travels
with the speed of light.

2. They have wavelength greater
than infrared light but smaller than
Radiowaves.

3. They have a lower frequency than
infrared light but greater than
radiowaves.

4. They are found between Radiowaves
and Infrared Waves.

USES

1. They are used in communication.
2.They are used in satellite TV.
3. They are used in cooking.
4. They are used to carry mobile phone
signal.

DISADVANTAGES

1. Exposure to microwaves can heat
the body tissues.

2. Exposure to high dose of
microwaves can cause eye damage
and even cataract.




RADIOWAVES

SOURCE

Radio waves can be generated by natural sources
such as lightning or astronomical phenomena; or
by artificial sources such as broadcast radio
towers, cell phones, satellites and radar.

PROPERTIES

1. They are electromagnetic wave which
travels
with the speed of light.

2. They have the highest wavelength.

3. They have the lowest frequency.

USES
  • They are used in communication
    to carry TV, radio and mobile
    signals.
  • They are used in wireless connection
    and bluetooth connection.
DISADVANTAGES

1. Exposure to radiowave can heat
the body tissues.

2. Exposure to high dose of
radiowaves can cause eye damage
and even cataract.




LENSES

They are used to refract the light and forms the image of an
objects. They are used in camera.

CONVEX LENSCONCAVE LENS

1.   It is a converging lens

2. It is thicker at the center
than at the edges

3. It has a real focus

4. It converges a parallel
beam of light on refraction
through it

5. It is used in microscope,
magnifying glass

6. Used to correct short sight

1.   It is a diverging lens.

        2. It is thinner at the center
than at the edges.

3. It has a virtual focus

4. It diverges a parallel beam
of light on refraction
through it.

5. Used in some telescopes

6. Used to correct long sight.

CONCAVE LENS

mages formed is virtual, upright
and smaller than the object.

CONVEX LENS




KEY TERMS

  • Waves:- Waves are oscillations or disturbance that
    transfer energy from one point to another.
  • TRANSVERSE WAVES:- In transverse waves, the oscillations move
    perpendicular to the direction of the wave.
  • CRESTS :- It is the height of the wave.
  • AMPLITUDE :- It is the maximum displacement
    of the wave from the mean
    Position.
  • LONGITUDNAL WAVES :- In longitudnal waves, the oscillations move
    parallel to the direction of the wave.
  • FREQUENCY :- It is the number of waves
    passing each second.
    It is measured in Hertz (Hz)
  • WAVE SPEED:- It is the distance travelled
    by the wave each second.
  • TROUGH :- Trough
    It is the depth of the wave.
  • TIME PERIOD :- The time it takes for one
    wave to travel.
  • WAVELENGTH :- The distance between
    two consecutive crests
    or trough.
  • REFLECTION :- Reflection is the phenomenon of bouncing
    off the wave when it hits a medium.
    eq: Reflection of light wave when it hits a plain
    Mirror.
  • REFRACTION :- 1. Bending of light as it travels from one medium to
    another.

2. Reflection on a smooth surface.

3. Reflection on a rough surface.

  • OPAQUE :- Opaque objects
    does not allow the
    light to be transmitted
    but absorb all
    the light.
  • TRANSLUCENT :- These objects
    allow some part
    of the light to be
    transmitted.
  • TRANSPARENT :- They allow the
    light to be transmitted
    through them
    without any absorption.
  • ULTRASOUND:- It is the frequency of sound greater than 20,000
    Hz.
  • EARTHQUAKE:- Earthquake takes place
    when the rocks or the tectonic
    plates in the Earth’s Crust
    or the upper Mantle Moves
    due to forces inside the Earth.
  • SEISMOLOGY:- Seismology is the study of
    Seismic Waves.
  • SEISMIC WAVES:- Seismic Waves are the shock waves
    which originate when the forces inside
    the earth moves the rocks or
    the tecctonic plates. These waves travel
    through the Earth and also across its surface.
  • ELECTROMAGNETIC SPECTRUM:- It is the spectrum with all the
    electromagnetic waves arranged
    in the order of the increasing wavelength
    or frequency.
  • FOCUS:- Principle
    Focus or
    Focal points
    where the
    parallel rays
    meet or
    appears to meet.
  • LENS:- They are used to refract the light and forms the
    image of an
    objects. They are used in camera.
  • CONVEX LENS:- 1. It is a converging lens.
  • CONCAVE LENS:- 1. It is a diverging lens.
  • FOCAL LENGTH:- The distance between
    the focus and the
    center of the lens.




Disclaimer:

I have tried my level best to cover the maximum of your specification. But this is not the alternative to the textbook. You should cover the specification or the textbook thoroughly. This is the quick revision to help you cover the gist of everything. In case you spot any errors then do let us know and we will rectify it.

References:

BBC Bitesize

Wikipedia

Wikimedia Commons

Image Source:

Wikipedia

Wikimedia

Commons

Flickr

Pixabay

Make sure you have watched the above videos and are familiar with the key definations before trying these questions. It is also good to time yourself while doing these questions so that you can work on the speed as well.

P-15 Light