IGCSE Physics - Pearson Edexcel - GLOSSARY DEFINITIONS ONLY - COMPLETED Flashcards
1
Q
What is absorption?
A
Absorption is the opposite of reflection. Soft foam surfaces absorb sound, matt black surfaces absorb light and heat.
2
Q
What does ‘accelerating’ mean?
A
Getting faster, increasing velocity.
3
Q
What is an alternating voltage?
A
A voltage that is continuously changing in value and direction.
4
Q
What is amplitude?
A
The maximum distance moved by a vibrating object from its equilibrium position.
5
Q
What is the angle of incidence?
A
The angle between the incoming ray and the normal.
6
Q
What is the angle of reflection?
A
The angle between the reflected ray and the normal.
7
Q
What is the angle of refraction?
A
The angle between the refracted ray and the normal.
8
Q
What is apparatus?
A
Equipment used in investigations and experiments.
9
Q
What are ‘applications’?
A
Uses
10
Q
What are asteroids?
A
Small rocky objects orbiting the Sun, mostly found between the orbits of Mars and Jupiter.
11
Q
What are atoms?
A
Small particles from which everything is made.
12
Q
What does ‘attract’ mean in physics?
A
Pull together.
13
Q
What are bacteria?
A
Single-celled organisms, some types of which cause illness.
14
Q
What are calories?
A
Calories are a unit of measurement which is no longer used, except for measuring the amount of energy in food.
15
Q
What are cells in physics?
A
Sources of electrical energy.
16
Q
What are circuits?
A
In electricity and electronics, circuits are complete conducting paths for electricity. Circuit is sometimes used as a term for electronic apparatus.
17
Q
What is a collision?
A
Two or more moving objects hitting each other.
18
Q
What is a comet?
A
An object often made of ice and rocks that orbits the Sun in an elongated orbit.
19
Q
What does ‘compressed’ mean?
A
Squeezed into a very small place.
20
Q
What is compression?
A
Squashing together.
21
Q
What is thermal conduction?
A
The moving of heat through a solid.
22
Q
What is electrical conduction?
A
The moving of electric charge through matter.
23
Q
What is a conductor?
A
A material that allows electricity to flow through it easily.
24
Q
What are control rods?
A
Control rods are rods used in a nuclear reactor to slow down or stop a nuclear chain reaction.
25
What is convection?
The movement of heat in a fluid (a fluid meaning a gas OR a liquid) as the fluid expands and rises when warmed.
26
What is a core?
The centre of something as in, for example, the Earth's core.
27
What is deceleration?
Getting slower, decreasing velocity.
28
What does 'deflected' mean?
Made to change direction.
29
What is diameter?
The width of a circle, cylinder or sphere.
30
What is a dimmer switch?
A device used to alter the brightness of a bulb or light.
31
What is displacement?
The distance a particle has moved from its equilibrium (undisturbed) position.
32
What does 'dissolved' mean?
Broken down into tiny particles or molecules by the action of a liquid - for example, sugar dissolving in water.
33
What is the Doppler effect?
The change in frequency (and wavelength) caused by the relative movement of the source of the waves or the observer.
34
What is the drag coefficient?
A measure of how easily an object can move through a fluid (a liquid OR a gas).
35
What are electrical insulators?
Materials that do not allow electric current to pass through them.
36
What is an electrode?
A metal plate or rod by which electricity can enter or leave an electrical device.
37
What is the electromagnetic spectrum?
The family of waves including radio waves, microwaves, infrared waves, visible light, ultraviolet and x-rays.
38
What are elements in chemistry?
Elements are pure substances made up of only one type of atom.
39
What are 'elements' in general use?
Part of something.
40
What is an emission?
Something emitted from a system.
41
What does 'emitted' mean?
Given out.
42
What does 'evaporate' mean?
To change from a liquid to a gas (usually at a temperature lower than the boiling point of the liquid).
43
What does 'exerted' mean?
Acted on.
44
What is the filament?
The coil of wire in a bulb that glows when electricity passes through it.
45
What is fission?
The breaking up of an atom into smaller parts.
46
What is 'flex'?
Wire
47
What is a force?
A push or a pull.
48
What are fossil fuels?
Substances used to provide energy when burned that have formed over millions of years from dead animal or vegetable matter.
49
What is a fraction?
A part of. Sometimes represented mathematically as a ratio of a smaller number over a larger number - for example, 1/2 for a half.
50
What is frequency?
The number of waves or vibrations made each second.
51
What is friction?
A force between two solid surfaces trying to move across each other that tries to stop movement happening.
52
What is a fusion reaction?
When the centres of atoms (nuclei) join together.
53
What is a generator?
A device that transfers mechanical energy to electrical energy - that is, a source of electrical energy.
54
What does 'glow' mean?
Emit light.
55
What is a gradient?
The slope of a line or surface.
56
What is gravitational field strength?
How great the effect of gravity acting on an object is, usually given as force per unit mass.
57
What is gravity?
The force that objects with mass exert on each other.
58
What is half-life?
The length of time it takes for the activity of an amount of a radioactive substance to halve.
59
What is a halogen light bulb?
A light bulb that contains a small amount of a halogen such as iodine or bromine.
60
What are heating elements?
Coils of wires used to transfer electrical energy to heat energy.
61
What is a hemisphere?
Half a sphere, as in the northern hemisphere referring to the part of the Earth above the equator.
62
What is hydroelectric power?
Electrical energy produced from the energy in water stored high above ground level in mountain lakes and reservoirs.
63
What does 'induced' mean?
Created, caused, produced.
64
What are inkjet printers?
Printers that create an image by directing droplets of ink onto paper.
65
What is an insulator?
A material through which it is very difficult or impossible for electricity to flow.
66
What does 'inversely proportional' mean?
Something varying such that it decreases by equal amounts as some other factor increases by equal amounts.
67
What is kinetic energy?
The type of energy that a moving object stores.
68
What does LED stand for?
Light Emitting Diode
69
What is a light emitting diode (LED)?
A material that gives off light when a current passes through it.
70
What are light gates?
Electronic systems that are used to switch something on or off, like a digital clock when a light beam between a light source and a detector is broken.
71
What are longitudinal waves?
Waves which the vibrations are along the direction in which the wave travels.
72
What is a magnetic field?
A place where we can detect magnetism.
73
What is magnification?
How many times bigger - for example, a magnification of two indicates it is twice as big.
74
What is mass?
The amount of matter in an object; mass of an object determines how easy it is to speed up or slow down.
75
What does 'metric' mean?
Related to a system of units of measurement based on kilograms, metres and seconds - for example, SI units are metric.
76
What is a moderator?
A material used in nuclear reactors to make neutrons move more slowly.
77
What are molecules?
Groups of atoms joined together.
78
What does 'negatively charged' mean?
Has more negative charges than positive charges.
79
What is a non-porous material?
A material that does not allow liquids to pass through it.
80
What is a non-renewable energy source?
An energy source that will not last forever - for example, a fossil fuel like coal will run out eventually.
81
What is the normal?
A line at 90 degrees to the surface.
82
What does 'nuclear' mean?
To do with the nucleus of an atom - for example, the forces that hold neutrons and protons tightly together in the nucleus is a nuclear force.
83
What is an optical telescope?
An instrument that we use to see distant objects using visible light.
84
What is an orbit?
The path of a planet around a star or a satellite around a planet.
85
What are orbital speeds?
The speeds of objects as they circle other objects - for example, the Moon going around the Earth.
86
What are ores?
Many chemical elements are bound up with other elements in rocks; these rocks are called ores.
87
What is an oscilloscope?
A device used to observe waves and vibrations.
88
What is the ozone layer?
A layer high above the Earth's surface that contains a lot of ozone (O↓3).
89
What is a parabola?
A particular shape of curved surface used to focus light, heat, radio waves, and so on, to a particular point.
90
What is a parallax error?
An error caused by not reading a scale on a ruler or other measuring instrument by looking at the scale straight on (at a right angle to the scale).
91
What is penetrating power?
The measure of the ability of a wave to travel through objects.
92
What does 'perpendicular' mean?
Upright or at right angles (90 degrees to something).
93
What are phenomena?
Events, occurrences.
94
What are phenomena?
Events, occurrences.
95
What is photosynthesis?
The process in green plants that uses light from the Sun to produce energy for the plant to grow.
96
What are photovoltaic cells?
Devices that transfer energy from light (typically the Sun) into electrical energy. Photovoltaic cells are used in renewable energy projects. They are not to be confused with solar heat exchangers that transfer heat from the Sun to water, allowing energy to be stored in tanks of heated water.
97
What is pitch (of a sound)?
The interpretation of the frequency of a sound by a person's brain/ear.
98
What is the pivot?
The point around which something can turn or rotate.
99
What are plugs and sockets?
Plugs and sockets are the most common way to obtain electrical energy from the mains supply.
100
What is polarity?
A term used to describe which parts of a magnet are north or south or which parts of an electrical circuit are positive and negative.
101
What are prisms?
Transparent, triangular shaped pieces of glass or plastic.
102
What does 'proportional' mean?
Something varying such that it increases by equal amounts as some other factor increases by equal amounts.
103
What does 'quartered' mean?
Decreased by a factor of four (that is, 1/4 of the original).
104
What does 'radioactive' mean?
Having an unstable nucleus that will emit particles and waves to achieve a more stable nucleus.
105
What is a radioisotope?
A radioisotope is an isotope of an element that has the same number of protons in the nucleus but different numbers of neutrons. A radioisotope is unstable, radioactive; radioisotopes are also called radioactive isotopes.
106
What is ratio?
A way of comparing the quantities of things - for example, a ratio of 3:1 means there is three times the amount of one thing compared to the other.
107
What is a reaction?
The response to an action; in physics, reaction is the equal force that acts as a result of an action force, equal in size but opposite in direction.
108
What are rectifier circuits?
Circuits used to change alternating currents into direct currents.
109
What is red-shift?
Red-shift is when emitted waves have their wavelength increased - that is, moved to the red end of the spectrum.
110
What is the refractive index?
A measure of the change in speed a wave experiences when it travels across the boundary between two media, e.g. air and glass. The index also describes how much the direction of the wave changes; n = sin i/sin r.
111
What is relative charge?
The charge compared with the charge on an electron.
112
What is renewable energy?
Renewable energy supplies are energy supplies which will not be completely used up in time like the energy from the Sun, wave energy, wind energy, and so on.
113
What does 'repel' mean?
Push away.
114
What are repulsive forces?
Forces that push away from each other.
115
What is resistance?
The difficulty current experiences in a circuit.
116
What is the resultant force?
The total effect of two or more forces acting on an object; sometimes referred to as an unbalanced force.
117
What does 'rotate' mean?
To turn or spin about an axis (central point).
118
What is rotating?
Turning
119
What does 'scanned' mean?
Looked at over an area, as in scanning pages from a book in a photocopier.
120
What is a solenoid?
A long coil.
121
What is sonar?
A method of using sound waves to detect objects and measure their distance.
122
What is a spiral galaxy?
A very large group of stars that forms a spring-like winding shape.
123
What does 'squared' mean in maths?
Something multiplied by itself.
124
What does 'sterilised' mean?
Made free of dirt and bacteria.
125
What does 'sterilise' mean?
Remove all bacteria and germs.
126
What is a stroboscope?
Apparatus that produces short bright flashes of light at regular intervals (that is at a known frequency, flashes per second). A stroboscope allows the frequency to be varied; this is used to allow a series of images of a moving object to be captured photographically or to determine the speed of rotating objects.
127
What does 'subtract' mean?
Take away from.
128
What is a sum?
The result of adding things together.
129
What is terminal velocity?
The maximum speed that a moving object is able to reach.
130
What does 'thermal' mean?
Relating to heat; also used to describe upward air currents called convection.
131
What is a thermistor?
A conductor whose resistance changes a lot when its temperature changes.
132
What is thrust?
A type of pushing force, like the thrust of rocket motors.
133
What is a time period (as it relates to waves/vibrations)?
The time needed to make one complete wave or vibration.
134
What are tracers?
Substances that can be detected to show the movement of liquids through a person's body or pipes in machinery.
135
What is a transformer?
A device used to change alternating voltages.
136
What are transverse waves?
Waves which the vibrations are at right angles to the direction in which the wave is moving.
137
What does 'trebled' mean?
Increased by a factor of 3 - that is, 3x the original.
138
What is a tuning fork?
A steel instrument that when it vibrates produces sound waves of a constant frequency and wavelength.
139
What is an unbalanced force?
A non-zero resultant force.
140
What does 'unstable' mean?
Likely to change - if referring to an object, it means to tip over. In the case of a radioactive isotope, it means to emit particles that change the make-up of a nucleus.
141
What is upthrust?
An upward force acting on something; an object in a liquid or gas will have an upward force acting on it called the buoyant upthrust (to do with floating).
142
What is a vacuum?
Containing no matter at all; the space between stars is a nearly perfect vacuum. A vacuum flask has a gap around the inner container that is completely emptied of any matter.
143
What does 'vertical' mean?
Upwards, at right angles to the ground.
144
What does 'vibrate' mean?
Move continuously back and forth.
145
What is visible light?
Waves that can be detected by the eye.
146
What is the voltage?
The amount of energy transferred to each coulomb of charge that passes.
147
What is the wavelength?
The distance from one point on a wave to the same point on the next wave.
148
What are waves?
Vibrations which carry or move energy.
149
What is weight?
The force of gravity acting on a body.
150
What is the 'weightless' condition?
The condition in which a body does not experience the force we call weight. If you stand on weighting scale in a lift that is accelerating toward the Earth at 10 m/s^2 the scales will show that you weigh nothing - this is just one way in which weightlessness can happen.
