Flashcards
Waves 2
Flashcards do conjunto (45)
- 1Define the principle of superposition of wavesWhen two similar types of waves meet at a point the resultant displacement at that point is equal to the sum of the displacements of the individual waves
- 2How do noise cancelling headphones use the principle of superposition of wavesA microphone on the outside of the headphones detects background noise, the speakers inside the headphones then produce waves that try to cancel out all external sound
- 3Define superpositionThe overlap of two waves at a point in space
- 4Define interferenceInterference is the superposition of two progressive waves from coherent sources to produce a resultant wave with a displacement equal to the sum of the individual displacements from the two waves
- 5Define constructive interferenceThe superposition of two waves in phase so that the resultant wave has greater amplitude than the originals waves
- 6What is the result of two progressive waves that interfere when they are in phaseConstructive interference
- 7What is intensity directly proportional toAmplitude^2
- 8What happens when two progressive waves interfere, when they are antiphaseDestructive interference
- 9Define destructive interferenceThe superposition of the waves in antiphase so that the waves cancel each other out and the resultant wave has smaller amplitude than the original waves
- 10How is the intensity of a wave affected by destructive interference and constructive interferenceSince intensity is directly proportional to amplitude ^2, constructive increases the intensity and destructive decreases the intensity
- 11Define an interference patternA pattern of constructive and destructive interference formed as waves overlap
- 12Define coherenceCoherence is when two wave sources, or waves, halve a constant phase difference and frequency
- 13What is needed for a stable interference patternFor the waves to be coherent
- 14Define maxima and minimaMaxima is the point of greatest amplitude in an interference pattern, produced by constructive interference. Minima is the point of lowest amplitude in an interference pattern, produced by destructive interference
- 15Define path differenceThe difference in distance travelled by two waves from their source to a specific point
- 16Describe the path difference when two waves will arrive at the point in phaseThe path difference must be interference multiples of the wavelength, eg 0lambda, nlambda etc
- 17What is the path difference when the two waves always arrive in antiphase, and what does it producePath difference must be 2n+1 / 2 lambda, not an interger of lambda, producing destructive interference
- 18What is the path difference at the central maximaZero
- 19What is the relationship between the path difference and phase differencePhase difference is 2 x n, replace lambda with pi. Eg 2 lambda path difference = 4 pi phase difference
- 20Describe an experiment for investigating interference in soundTwo loud speakers connected to the same signal generator, emits coherent sound waves. The waves overlap, causing interference pattern comprises of maxima and minima. Detect these variations with a microphone.
- 21Describe an experiment for investigating interference in microwavesA single microwave source used, with a pair of slits to create two coherent sources. The diffracted waves overlap to create an interference pattern to be detected with a microwave reviewer connected to a voltmeter or oscilloscope. Positions of maxima and minima can be recorded on paper
- 22What do you need to produce an interference patternTwo coherent light sources
- 23What is a monochromatic source of light?Light of a single frequency
- 24How can you achieve a monochromatic source of light in an experimentBy using a colour filter that only allows a specific frequency of light to pass
- 25Describe the set up for the young double slit experiment/
- 26Describe the young double slit experimentA lamp is placed behind a colour filter to produce a coherent source of monochromatic light. This light is then directed using a single narrow slit, which then diffracts using double slits, producing two coherent light sources. This light then produces an interference pattern on the screen
- 27What does the young double slit experiment demonstrateThe wave nature of light, can also be used to find the wavelength of various colors of visible light
- 28Name an equation for wavelength involving the double slit experimentWavelength = distance between two slits x distance between two maxima/minima
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Distance between slits and screen - 29Describe an experiment to determine the wavelength of monochromatic light from a laserShine the laser through the double slit onto a screen. Use the equation wavelength = ax/d to determine the wavelength.
- 30Define a standing waveA wave that remains in a constant position with no net transfer & is characterized by its nodes and antinodes
- 31Define a stationary waveA wave that remains in a constant position with no net transfer & is characterized by its nodes and antinodes
- 32How are stationary waves formedWhen two progressive waves with the same frequency traveling in opposite directions are superposed. The nodes are when the two waves are always in antiphase, an antinode is formed when they are always in phase
- 33Define a nodeA point in a stationary wave where the amplitude is always zero
- 34Define an antinodeA point in a stationary wave where the amplitude is always at its maximum
- 35Name 2 differences between progressive and stationary waves, involving energy and wavelengthProgressive waves transfer energy in the direction of the wave, stationary waves have no net energy transfer. Wave length in P waves is distance between two adjacent points eg peaks, for S waves it is 2 x distance between adjacent nodes/antinodes.
- 36Name 2 differences between progressive and stationary waves involving phase difference and amplitudeIn p waves the phase difference changes across each cycle, for S waves all parts between 2 nods are in phase, and all parts on different sides of nodes are in antiphase. All parts of the p wave have the same amplitude, where as for the S wave, max amp occurs at antinode, and zero occurs at node
- 37Describe an experiment to form a stationary wave using microwavesSet up a microwave transmitter in front of a metal plate, with a microwave receiver in between. A stationary wave is formed by reflecting microwaves off of metal sheet. You move the receiver between the two to detect nodes and antinodes. With this you can calculate the wavelength
- 38Define the fundamental mode of vibrationA vibration at the fundamental frequency
- 39Define the fundamental frequencyThe lowest frequency at which an object (eg string fixed at both ends) can vibrate
- 40Define harmonicsA harmonic is an interger multiple of the fundamental frequency
- 41Describe the equipment used when investigating vibrations on a stringString fixed at one end, and the other fixed on a pulley with massess
- 42Describe the equipment used when investigating stationary waves within soundSpeaker connected to a signal generator, a solid surface and a microphone to move in between
- 43Describe a stationary wave in a tube open at one end and closed at the otherNode at closed end antinode at open end
- 44Describe a stationary wave in a tube open at both endsAntinode at both ends
- 45Describe an experiment to measure the wavelength of lightSet up laser shining at piece of paper/screen, meter away is diffraction grating. In dark room, most light goes though grating, light interferes with itself producing interference pattern. Measure distance between maxima/minima, use these to calculate wavelength with lambda = ax/d
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- physics A level (M4 Chapter 12 Waves 2 ) FlashCards sobre Waves 2, criado por lizabeth rawson em 29-05-2021.
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- lizabeth rawson
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