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Definition
| Physical law stating charge is conserved in all interactions; it cannot be created or destroyed. |
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Definition
| A model used to describe the movement of charge in a circuit. Conventional current travels from + to -. |
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Definition
| Parts of an electric circuit. |
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Definition
| A material with a high number density of conduction electrons, and therefore a low resistance. |
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Definition
| Unit of electric charge. 1C = 1A x 1s |
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Definition
| A spectrum of dark lines across the pattern of spectral colors produced when light passes though a gas and the gas absorbs certain frequencies depending on the elements in the gas. |
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Definition
| A device used to measure electric current, connected in series with components. |
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Definition
| Is where energy is carried from one place to another. |
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Term
| Stationary wave/Standing wave |
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Definition
| Is where energy is stored rather than transmitted. |
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Definition
| Points in a stationary wave at which there is no displacement of the particles at any time. |
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Definition
| The point on a stationary wave where the displacement of the particles varies by the maximum amount. |
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Definition
| The resistance of a battery or cell, measure in ohms. |
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Definition
| A graph to show how the electric current through a component varies with the P.D across it. |
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Definition
| An unit of energy used by electricity companies when charging for electricity. |
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Definition
| The addition of two or more waves that results in a new wave pattern. |
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Definition
| Two waves with a constant phase relationship. |
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Definition
| The average velocity of an electron as it travels through a wire due to P.D. |
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Definition
| The ratio of the product of resistance and cross-sectional area of a component and its length. |
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Definition
| A form of electromagnetic wave with wavelengths between (10^-6) to (10^-9)m. |
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Definition
| Whole number multiples of the fundamental frequency of a stationary wave. |
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Definition
| A discrete, indivisable quantity. |
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Definition
| Unit of angle or phas difference. One radian is the angle subtented at the centre of a circle by an arc of circumference that is equal in length to the radius of the circle. |
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Definition
| A material with a smaller number density of conduction electrons than a conductor, therefor a higher resistance. |
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Definition
| A type of circuit where the components are connected end to end and therefore provide only one path for the electric current. |
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Definition
| A series of vibrations that transfer energy from one place to another. |
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Definition
| The smallest difference between one point on a wave and the identical point ofn the next peak. Measured in metres. |
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Definition
| The theory that states all objects can exhibit both wave and particle properties. |
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Definition
| The minimum energy required to release an electron from a material, measured in joules. |
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Definition
| An experiment to demonstarate the wave nature of light via superposition and interference. |
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Definition
| A type of circuit where the components are connected in two or more branches and therefore provide more than one path for the electric current. |
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Definition
| A component that reduces it resistance when light shines on it due to photoelectric emission of electrons. |
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Definition
| A collection of waves with a range or frequencies, for example; the visible spectrum. |
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Definition
| A line relating to a specific frequency either missing from an absorption spectrum or present in an emission spectrum. |
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Definition
| A component that changes it resistance depending on temperature. An NTC thermistor's resistance reduces as the temperatre increases. |
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Term
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Definition
| One electron volt is the energy charge of an electron when it moves through a P.D of one volt. Its value is 1.60x10^-19 |
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Definition
| A pattern of colors of light, each color having a specific wavelength. |
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Definition
| One of the specific energies an electron can have when in an atom. |
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Definition
| A device that converts kinetic energy into electrical energy. |
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Definition
| A self propagating transverse wave that does not require a medium to travel through. |
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Definition
| A fluid that contains ions that are free to move and hence conduct electricity. |
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Definition
| A component that changes its resistance with changes in the light intensity. (Dark conditions = High resistance) |
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Definition
| A component that allows electric current to pass through it in one direction only and that emits light when a P.D is applied across it. |
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Definition
| A form of electromagnetic wave with wavelengths of (7.4x10^-7) and (10^-3)m. |
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Definition
| A material with a very small number density of conduction electrons, therefore leading to a very high resistance. |
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Definition
| The energy incident per square metre of a surface per second. 1Wm^-2 |
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Term
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Definition
| Light waves with a single frequency or wavelength. |
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Term
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Definition
| The electric current through a conductor is proportional to the P.D across it, provided that the physical conditions reain the same. |
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Definition
| Unit of resistance 1ohm = 1VA^-1 |
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Definition
| The frequency in a harmonic series where a stationary wave forms. |
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Definition
| An electrical component designed to heat up, melt and break the circuit when a specific amount of electric current passes through it. It is used as a safety device. |
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Definition
| The electrical energy transferred per unit charge when one form of energy is converted into electical energy. easured in volts. |
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Definition
| Negatively charged sub-atomic particle. Conduction electrions travel around a circuit to create an electric current. |
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Term
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Definition
| When a wave spreads out after passing around an obsticle or through a gap. |
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Definition
| An equation expressing the wavelength of a particle as a ratio of planck's constant and the particle's momentum. |
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Definition
| The process of diffracting an electron through a gap (usually between atoms in a crystal structure). It is an example of wave-particle duality |
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Definition
| The movement of electrons (usually around a circuit) from - to +. |
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Definition
| A form of electromagnetic wave with a wavelength between (10^-1) and (10^4)m. |
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Definition
| The elctrical energy transferred per unit charge when electrical energy is converted into some other form of energy. |
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Definition
| A type of circuit containing two components designed to divide up the P.D in proportion to the resistances of the components. |
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Definition
| A transverse wave oscillating in one plane only. |
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Definition
| The process of turning an unpolarised wave into a plane polarised wave. |
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Term
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Definition
| The emission of electrons from the surface of a material when electronmagnetic radiation is incident on the surface |
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Term
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Definition
| A quantum of light, often described as a particle of light. |
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Term
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Definition
| Constant used in physics. h=6.63x10^-34 Js |
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Definition
| A form of electromagnetic wave with wavelengths of (10^-9) to (3.7x10^-7) |
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Definition
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Definition
| Unit of Power 1W = 1Js^-1 |
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Term
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Definition
| A device used to measure the P.D across a component. It is connected in parallel. |
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Term
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Definition
| A spectrum produced by a material that contains only certian frequencies due to electron transistions between energy levels. |
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Term
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Definition
| A physical law describing the change in intensity of a transverse wave passing through a polaroid analyser. |
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Term
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Definition
| A form of electromagnetic wave with wavelengths between (10^-4) and (10^-1)m. |
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Term
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Definition
| When waves rebound from a barrier, changing direction but remaining in the same medium. |
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Term
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Definition
| When waves change direction when they travel from one medium to another due to a difference in the wave speed of each medium. |
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Definition
| A wave in which the oscillations are at a right angle to the direction of travel. |
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Term
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Definition
| Physical law stating that energy cannot be created or destroyed, but can be transformed from one form to another. |
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Term
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Definition
| The sum of the currents entering any junction is also equal to the sum of the currents leaving the junction. |
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Term
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Definition
| The sum of the E.M.Fs is equal to the sum of the P.Ds in a closed loop. |
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Term
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Definition
| A wave where the oscillations are parallel to the direction of the wave. |
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Term
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Definition
| The principle that states that when two or more waves of the same type exist at the same place the resultant wave will be found by adding the displacements of each individual wave. |
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Term
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Definition
| The maximum displacement of a wave from its mean position, measured in metres. |
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Definition
| The number of oscillations per unit time, measure in Hertz. |
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Definition
| The time taken for one complete pattern of oscillation, measured in seconds. |
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Term
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Definition
| The distance any part of the wave has moved from its mean, measure in metres. |
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Term
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Definition
| The difference by which one wave leads or lags behinds another, measured in radians. |
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Term
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Definition
| V=IR. A property of a component that regulates the electric current through it. Measured in ohms. |
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Term
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Definition
| Q=IT. Measured in Coloumbs |
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Term
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Definition
| A flow of charge. Measure in amperes and is a vector quantity. |
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Term
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Definition
| A form of electromagnetic wave with wavelengths of (3.7x10^-7) to (7.4x10^-7)m |
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Term
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Definition
| A form of electromagnetic wave with wavelength of (10^-12) to (10^-7)m. |
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Term
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Definition
| The minimum frequency needed to free an electron from the surface. |
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Term
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Definition
| Wave sources that have a constant phase difference. |
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Term
| Principle of superposition of waves |
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Definition
| Constructive interference/waves in phase. Maxima produced when path difference is 0 or nλ. Minima produced when path difference is (n+1/2)λ. |
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Term
| How is a standing wave formed? |
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Definition
| Waves travel out fropm the centre and are reflected then interference /superpositioning occurs. |
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Term
| Explain the changes in an ammeter and a voltmeter when the temperature of a NTC thermistor is increased. |
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Definition
The resistance of the thermistor decreases as the temperature increases.
The total resistance of the circuit decreases.
The voltmeter reading decreases.
The current increases. |
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Term
| Does intensity change the energy of a photon? |
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Definition
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Term
| In waves, what is the relationship between intensity and amplitude? |
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Definition
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Term
| What are the charge carriers in metal? |
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Definition
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Term
| What is the equation for drift velocity? |
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Definition
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Term
| Are ionic crystals insulators? |
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Definition
| Yes and no. When molten it is a conductor as the free ions are the charge carriers. It is an insulator under its normal physical state as there is very little charge carriers. |
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Term
| In what situations do gases conduct electricity? |
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Definition
| Under a very high voltage. |
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Term
| Wht is the charge of an electron? |
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Definition
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Term
| What does a curve on a I/V characteristic graph mean? |
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Definition
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Term
| How does temperature affect the resistance of a metal wire? why does it affect it? |
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Definition
| It increases the resistance as the ions vibrate more due to the extra kinetic energy, the electrons then collide with them more often, losing energy. |
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Term
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Definition
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Term
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Definition
| It is the direction the current is allowed to flow in a diode. |
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Term
| What is the equation for power? |
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Definition
| P = IV, P = V^2/R, P = I^2R |
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Term
| What is the equation for total energy transferred? |
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Definition
| E = VIt , E = I^2Rt, E = V^2/Rt, P = Et |
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Term
| What values of fuses do you get? |
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Definition
| 3A and 13A (sometimes 5A). |
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Term
| Why does a battery have resistance? |
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Definition
| As the electrons move in the battery, they collide with the atoms in the battery - causing an internal resistance. |
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Term
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Definition
| It is the energy wasted per coulomb overcoming the internal resistance. |
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Term
| What are the equations to do with E.M.F? |
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Definition
| e = V + v, e = I(R+r), e = V + Ir. |
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Term
| In what type of circuit is the P.D the same across all components? |
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Definition
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Term
| In what type of circuit is the current the same across all points of the circuit? |
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Definition
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Term
| What is the equation for the speed of a wave? |
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Definition
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Term
| When unpolarised light reflects, does it become partially polarised? |
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Definition
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Term
| What do all EM waves have in common? |
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Definition
They all travel at the same speed in a vacuum.
They obey v = λf.
They are all transverse waves. |
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Term
| Which EM wave has the most energy? |
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Definition
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Term
| Which EM wave has the least amount of energy? |
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Definition
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Term
| Principle of superposition |
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Definition
| When two or more waves cross, the resultant displacement equals the vector sum of the individual displacements. |
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Term
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Definition
| The two points are at the same point in the wave cycle. |
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Term
| What conditions are required to get an interference pattern? |
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Definition
| The two sources must be coherent. |
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Term
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Definition
| The superposition of two progressive waves with the same wavelength, moving in oppersite directions. |
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Term
| In what conditions do you get the most diffraction from a gap? |
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Definition
| When the gap is the same size as the wavelength. |
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Term
| If the gap in diffraction is smaller than the wavelength, what happens to the waves? |
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Definition
| They are mostly reflected back. |
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Term
| Why do you use lasers in young's double slit experiment? |
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Definition
| Because it is coherent and monochromatic. |
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Term
| What is the equation for the fringe spacing in young's double-slit experiment? |
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Definition
x = (Dλ)/d
x - fringe spacing
λ - wavelength
D - distance from slits to screen
d - spacing between slits |
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Term
| How do you make interference patterns sharper? |
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Definition
| By diffracting the light through more slits. |
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Term
| What is the equation used for diffraction grating? |
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Definition
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Term
| When you diffract white light through a diffraction grating and produce a spectra, where you find the red and violet wavelengths? |
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Definition
Red - Outside
Violet - Inside |
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Term
| What are the equations expressing the energy carried by a photon? |
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Definition
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Term
| Why isnt photons measured in joules? |
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Definition
| Because it has such a tiny energy that is makes sense to have a smaller unit. |
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