# OCR Physics B (Advancing Physics) Yr 1 Glossary

Fully inclusive collection of the definitions for the 1st Yr. collected from the textbook, revision guide and checked against past mark schemes.

Acceleration, a
The rate of change of velocity (Vector)
1 of 133
Accuracy
A measure of how close a measurement is to the true value
2 of 133
Accurate
Close to the true value
3 of 133
Aliasing
Whenl lower frequency signals are created due to too lower sampling rate. These lower frequencies are not in the origional signal.
4 of 133
Alloy
A material composed of two or more metals, or a mixture of metals and other materials
5 of 133
Amorphous
Atoms are arranged with no large range order, they are arranged randomly within the structure
6 of 133
Amplitude of a wave
The maximum displacement from the equilibrium position
7 of 133
Analogue Signal
A signal that varies continuously and is not confined to defined levels
8 of 133
Antinode
A position of maximum amplitude of oscillation on standing wave
9 of 133
Antiphase
When two oscillations have a phase difference of pi radians or a path difference of half a wavelength
10 of 133
bit
The smallest unit of digital information
11 of 133
Brittle
Breaks by shattering on impact, it undergoes no plastic deformation before fracture
12 of 133
Brittleness
The tendency of a material to break by crack propagation
13 of 133
byte
A sequence of 8 bits, coded to represent 256 alternatives
14 of 133
Calibration
Determining the relation between output and true input value
15 of 133
Ceramics
Materials made up of bonded atoms with directional and local bonds
16 of 133
Conductance, G
The ratio of I/V for a circuit component (Unit in Siemens, S)
17 of 133
Coherence
Two sources of waves a coherent if they have a constant phase difference and the same frequency.
18 of 133
Compression
When two forces act in opposite directions to compress an object along the line of action of the forces
19 of 133
Conductivity, Ïƒ (Electrical)
A constant for electrical conductors, which refers to the degree to which a specified material conducts electricity (Unit S/m)
20 of 133
Conductor (Electrical)
A material which conducts electricity well because it has many free charge carriers
21 of 133
Conservation of Energy
During any interaction, the total energy before the interaction is the same as the total energy after the interaction
22 of 133
Conservation of Momentum
During any interaction, the total momentum before the interaction is the same as the total momentum after the interaction (N2)
23 of 133
Crack propagation
When the stress on a material is concentrated at the tip of a crack, often across a single bond, causing the crack to travel through the material from its surface.
24 of 133
Cross linking of polymers
When links are added across molecular chains within a polymer making the material stiffer by limiting the bond rotation
25 of 133
Crystalline
Particles in a material are arranged in a regular pattern over a large range
26 of 133
Current (Electrical)
The rate at which charge flows through a pointing an electrical circuit (Unit in Amperes, A)
27 of 133
Density, â´
The mass per unit volume
28 of 133
Diffraction
The spreading of waves after passing through a gap or past the edge of an obstacle. Spread increased for narrower gap or increased wavelength
29 of 133
Digital Signal
A signal that has defined levels and is represented by binary number
30 of 133
Dislocation
A defect in the regular structure of a crystal or crystalline region of a material. Mobile within a pure metal making it ductile.
31 of 133
Displacement, s
The distance travelled in a specified direction (Vector)
32 of 133
Dissipation
A transfer of thermal energy resulting in an increase in internal energy, often of the surroundings
33 of 133
Distance
The separation between two points in space, possibly along a curved path, with no reference to direction (Scalar)
34 of 133
Drift velocity
The mean velocity of charge carriers in a conductor carrying an electrical current
35 of 133
Ductile
A material that can easily be drawn into a wire without losing its strength
36 of 133
Edge Detection
Highlighting only the edges in an image / Multiplying pixel value by 4, then subtracting the total of the 4 neighbouring pixel values. If answer is negative the pixel is made 0 (black)
37 of 133
e.m.f, Îµ
The energy per unit charge given by any source of electrical supply to the charges set in motion.
38 of 133
Elastic Deformation
When the material will regain its original shape after the deforming stress is removed
39 of 133
Elastic Limit
The maximum stress at which an object returns to its original shape after the deforming stress is removed
40 of 133
Elastic strain energy
The energy stored in a material when it is deformed elasticaly / Can be found as area underneath a F-x graph or per unit volume for area underneath a stress-strain graph
41 of 133
Elasticity
The ability for a material to return to its original shape after the deforming stress has been removed
42 of 133
Electronvolt, eV
The work done/kinetic energy gained lk when an electron is moved through a potential difference of 1 volt
43 of 133
False Colours
Assigning different colours for pixel value ranges. Used to highlight different features of an image.
44 of 133
Focal length, f
The distance from the centre of the lens to the focal point F
45 of 133
Focal Point (Focus), F
The point where light from a very distant object on the axis of the lens is brought to a focus by the lens
46 of 133
Force, F
The rate of change of momentum (N2) / the 'push' or 'pull' of an object associated with a change in its momentum (Unit Newtons, N)
47 of 133
Fracture
When an object is broken into two or more pieces when placed under stress
48 of 133
Fracture Stress
The stress at which an object fractures (breaks)
49 of 133
Fundamental frequency
The smallest frequency of a standing wave, found when the node seperation is half a wavelength
50 of 133
Grain boundary
The line along which grains meet in a crystalline material
51 of 133
Gravitational Potential Energy, E-grav
The potential energy of a mass due to its position in a gravitational field
52 of 133
Hard
Difficult to scratch or dent
53 of 133
Hardness
A measure of how difficult it is to scratch or dent a material
54 of 133
Hooke's Law
For small extenstions, force is proportional to extension by F=kx
55 of 133
Hooke's Law region
The region of a stress strain graph where the stress is proportional to strain, material is deforming elastically
56 of 133
Impulse
The product FÎ”t summed over the whole action of a force on an object resulting in a momentum change, Î”p = Impulse
57 of 133
Increasing Brightness
Increasing the lightness of all pixels in an image / Adding a fixed value to all of the pixel values
58 of 133
Increasing Contrast
Increasing the range of pixel values in an image by multiplying all the pixel values by a fixed value greater than one.
59 of 133
Inertia
The tendency of any stationary object to remain stationary or of any moving object to continue with the same momentum (N1)
60 of 133
Insulator (Electrical)
A material which conducts electricity poorly because it has very few free charge carries
61 of 133
Intensity
The energy per unit time carried by a wave / the energy per unit area on a surface
62 of 133
Internal resistance, r
The resistance within a source of e.m.f that results in a drop of terminal p.d. when current is drawn from the source
63 of 133
Iterative model
A mathematical treatment where small changes to variables are made at regular time intervals, Î”t
64 of 133
Kinetic Energy, E-k
The energy possessed by an object by virtue of its motion
65 of 133
Kirchoff's 1st Law
At any electrical junction, the total current into the the junction = the total current out of a junction / Conservation of current
66 of 133
Kirchoff's 2nd Law
Around any electrical circuit, the sum of all the e.m.f.s = the sum of all the p.d.s / Conservation of energy
67 of 133
Limit of Proportionality
The end of the hookes law region on a stress-strain graph, material is still deforming elastically but not at a constant rate
68 of 133
Longitudanal waves
When the oscillation of a wave is in the same direction as its direction of travel
69 of 133
Malleable
Easy to hammer or press a material into a required shape
70 of 133
Malleability
A measure of how easily a material can be hammered of pressed into a required shape
71 of 133
Mass, m
The amount of matter in an object (Unit kg)
72 of 133
Metals
Materials made up of metalically bonded atoms with non-directional and delocalized bonds
73 of 133
Momentum, p
The product of the mass and velocity of an object (Vector)
74 of 133
Newton's 1st Law
A stationary object will remain stationary, and a moving object with continue moving with the same momentum unless an external force acts upon it
75 of 133
Newton's 2nd Law
When an external force acts on an object, it produces a change in momentum / Force = the rate of change of of momentum / F=ma for a constant mass
76 of 133
Newton's 3rd Law
For every action there is an equal and opposite reaction
77 of 133
Node
A position of minimum amplitude of oscillation on standing wave
78 of 133
Noise
Variations, which may be random, superimposed on a signal
79 of 133
Number density of charge carries, n
The number of mobile charge carriers per unit volume of a conductor
80 of 133
Path difference
The difference in distance travelled by two waves to the same point
81 of 133
Percentage Uncertanty
The uncertanty given as a percentage of the measurement
82 of 133
Phase
Describes the stage in a wave cycle
83 of 133
Phase difference
The difference in phase angle between two waves of the same frequency
84 of 133
Pixel
A single picture element
85 of 133
Plane wavefront
A wavefront which contains no curvature
86 of 133
Plastic Deformation
When a material undergoes permanent deformation and does not return to its original shape when the deforming stress is removed
87 of 133
Plasticity
Material can deform permanently
88 of 133
Polarized wave
When a transverse wave oscillates in a single plane only
89 of 133
Polycrystalline
A material that is composed of many small, differently oriented grains made up of regularly structured atoms within
90 of 133
Polymers
Materials made from long chains of molecules
91 of 133
Precise
Repeated measurements are close together
92 of 133
Precision
A measure of how close repeated measurements are to each other
93 of 133
Projectile
An object that is thrown or fired who's subsequent motion is affected by a gravitational field
94 of 133
Random Error
An error in the results of an experiment which varies each time for the same setup
95 of 133
Reducing Noise
Reducing the amount of random noise in an image / Replacing pixel values with the median of their neighbouring pixel values
96 of 133
Refraction
The change in direction of a wave passing from one medium to another caused by its change in speed
97 of 133
Refractive index, n
The ratio of the speed of light in a vacuum to the speed of light in a material
98 of 133
Resistivity, â´ (Electrical)
A constant for electrical conductors, which refers to the degree to which a specified material resists the flow of an electrical current (Unit Î©m)
99 of 133
Repeatable
An experiment can be repeated multiple times to achieve the same results
100 of 133
Reproducible
An experiment can be repeated by someone else using different equipment or results to achieve the same answer
101 of 133
Resolution
The smallest detectable change in input
102 of 133
Response time
The time interval between a change in input and the corresponding change in output
103 of 133
Scalar
A quantity with magnitude but no direction
104 of 133
Semiconductor
A material with intermediate conductivity between conductors and insulators, due to having a much lower density of free charge carries than conductors
105 of 133
Sensitivity
The ratio of the output to the input
106 of 133
Sensor Circuit
A circuit whose electrical properties depend upon environment variables and which can be used to monitor or measure those variables
107 of 133
Speed
The distance travelled by an object per unit time with no account to direction (Scalar)
108 of 133
Standing wave
The superposition of two progressive waves with the same wavelength, moving in opposite directions
109 of 133
Strain, Îµ
The ratio of extension to original length
110 of 133
Strain Gauge
A small electrical device which contains long lengths of coiled up wire on a foil back allowing it to detect deformation to a surface. Compression if resistance decreases and tension if restance increaseses.
111 of 133
Strength
A measure of how much a material can resist being deformed by a force without breaking
112 of 133
Strong
Large breaking stress, can withstand high stresses without deforming or breaking
113 of 133
Stiff
Difficult to bend or stretch, small extension per unit force
114 of 133
Stiffness
A measure of a material's resistance to stretching or bending
115 of 133
Superposition
When two or more waves meet their displacements can superimpose. The resultant displacement is the sum of the displacements at a given instant
116 of 133
Systamatic Error
An error in the setup of an experiment which is the same for every repetition using the same setup
117 of 133
Tension
When two forces act in opposite directions to stretch an object along the line of action of the forces
118 of 133
Transverse waves
When the oscillation of a wave is perpindular to its direction of travel
119 of 133
Threshold frequency
The minimum frequency of light that will eject photoelectrons from a given surface
120 of 133
Tough
Large energy required to break or create new surface area
121 of 133
Toughness
A measure of how much energy a material can absorb before breaking
122 of 133
Vector
A quantity with both direction and magnitude
123 of 133
Velocity
The change in displacement of an object per unit time (vector)
124 of 133
Wavefront
An imaginary line or surface that moves along with a wave. All points on the wavefront have the same phase.
125 of 133
Work function, É¸
The minimum energy required to eject photoelectrons from a given surface
126 of 133
Yield Stress
The stress at which a large amount of plastic deformation takes place with a constant or reduced load
127 of 133
Ultimate Tensile Strength
The maximum stress a material can withstand before breaking
128 of 133
Un-Polarized wave
When a transverse wave oscillates in a randomly changing plane
129 of 133
Young's Modulus, E
A measure of the stiffness of a material given by the ratio of stress over strain
130 of 133
Valid
The results answer the origional question
131 of 133
Validity
A measure of how well the results answer the origional question
132 of 133
Zero error
The output for zero input
133 of 133

## Other cards in this set

### Card 2

#### Front

A measure of how close a measurement is to the true value

Accuracy

### Card 3

#### Front

Close to the true value

#### Back ### Card 4

#### Front

Whenl lower frequency signals are created due to too lower sampling rate. These lower frequencies are not in the origional signal.

#### Back ### Card 5

#### Front

A material composed of two or more metals, or a mixture of metals and other materials

#### Back ## Comments

No comments have yet been made

## Similar Physics resources:

See all Physics resources »See all Definitions resources »