Term
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Definition
| The flow of charge over time, between two points. Measured in Amperes, (A) and 1A of current is equivalent to 1Cs-1 |
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Definition
| The amount of charge that flows past a point with 1A current in 1 second. Measured in Coulombs (C) |
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Definition
| The ratio of voltage to current through a component |
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Term
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Definition
| For a metallic conductor, at constant temperature, the current in the conductor is directly proportional to the potential difference across its ends |
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Definition
| The resistance of a material, multiplied by its cross sectional area, per unit length |
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Term
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Definition
Temperature dependant resistors:
PTC - Positive temperature coefficient
NTC - Negative temperature coefficient |
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Term
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Definition
| Light Emitting Diodes - Semiconductors & only allow current through in one direction (diode) |
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Term
| Voltage / Potential Difference |
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Definition
| The energy transferred from charge in a circuit to a component (energy transferred per unit charge - V=W/Q) |
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Term
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Definition
| E.m.f. - Energy transferred from supply (battery/cell/supply) to a circuit (energy transferred per unit charge - E=W/Q) |
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Definition
| The rate of transfer of energy - Measured in Watts (J/s) |
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Term
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Definition
| Unit of Power - Equivalent to the transfer of one Joule per Second (1W=1J/1s) |
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Term
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Definition
| Equal to the current multiplied by the voltage, multiplied by the time |
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Term
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Definition
| One Kilo-Watt Hour - equivalent to the energy transferred to a 1KW device operating for one hour |
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Term
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Definition
| The resistance produced inside a supply of e.m.f. - due to chemicals (cell), wires or components (supply) in the circuit |
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Term
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Definition
| This is the potential difference across the two terminals of the supply |
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Term
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Definition
| This is the difference in volts, between the e.m.f. and the Terminal p.d. |
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Term
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Definition
| The sum of any current entering a junction is equal to the sum of the current leaving the junction (conservation of charge) |
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Term
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Definition
| The Sum of the e.m.f. around a circuit loop is equal to the sum of the p.d.s around the same loop (conservation of energy) |
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Term
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Definition
| The distance from the point on a wave to the line of undisturbed positions |
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Term
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Definition
| The maximum displacement of any point on a wave - proportional to the volume of sound waves |
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Term
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Definition
| The distance from any point on a wave to the next exactly similar point - distance of one full cycle) |
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Term
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Definition
| The number of complete oscillations per second - Hz |
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Term
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Definition
| The rate of energy transmitted per unit area, perpendicular to the wave velocity |
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Term
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Definition
| The speed at which the energy is transmitted |
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Term
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Definition
| Occurs where waves impact an impermeable barrier & change direction and become anti-phase to the incident wave |
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Term
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Definition
| A wave that has wave speed and therefore carries energy from one place to another |
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Term
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Definition
| This states that the Intensity (& therefore Amplitude) of a resultant wave after passing through a polarising filter is proportional to the cosine of the incident angle to the direction of the polarising filter |
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Term
| Principle of superposition of waves |
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Definition
| This states that when two waves interfere with each other, the resultant wave is proportional to the algebraic sum of the two waves’ displacement |
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Term
| Constructive Interference |
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Definition
| This occurs when the algebraic sum of the displacements produces an increased amplitude resultant wave |
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Term
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Definition
| This occurs when the algebraic sum of the displacements produces a reduced amplitude resultant wave |
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Term
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Definition
| This is the spreading out of a wave as it passes through a gap or around an edge and is proportional to the difference of the aperture and the wavelength |
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Term
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Definition
| These are waves that are reflected back onto themselves and are in anti-phase (180° out of phase). However, due to their opposite direction of movement, they combine constructively and destructively at the same point, varying with time |
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Term
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Definition
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Term
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Definition
| Point of maximum amplitude which oscillates. |
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Definition
The minimum frequency of a standing wave
for a given system or arrangement |
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Term
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Definition
| This is the effect of exposing a charged zinc plate attached to an electroscope to Ultraviolet light. This proves, as the electroscope reduces in reading, that the light must be discharging the plate. This is evidence for the particle model of light (photons), contradicting the wave model we have used before |
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Definition
| The minimum frequency required to release electrons from the surface of a metal |
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Term
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Definition
| The minimum amount of energy required by an electron to escape a metal’s surface |
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Term
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Definition
| This is the maximum kinetic energy of an electron after it escapes the surface of the metal |
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Term
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Definition
| This relates a particle’s momentum to its wavelength |
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Term
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Definition
| This is light that comprises of the full spectrum of visible light |
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Term
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Definition
| This is the spectra emitted (given off) by a body when white light is passes through it and then is re-emitted. The black lines show the spectra that hasn’t been absorbed & then re-emitted. This occurs for isolated atoms (body of gas) – Where the electrical forces between atoms are negligible |
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Term
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Definition
| This is the spectra emitted by white light that has passed through a body & is not interfered with. The black lines show the spectra that have been absorbed. These occur when EM radiation is absorbed by isolated atoms (body of gas). An electron absorbs a photon of the correct energy to allow it to make a transition to a higher energy level |
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Term
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Definition
| These are the levels of energy that an electron can have inside an atom |
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