Waves And Oscillation 2 Flashcards
Define superposition (1)
-the combination of 2 or more waves to form a resultant wave
State the principle of superposition (2)
-the resultant displacement is the vector sum of the individual displacement due to each other
-when 2 waves are of small or big amplitude, they either cancel out or add up
Define phase (1)
-the measurement of the position of a certain point along the wave cycle
Define standing waves (1)
-a standing waves is the superposition of 2 progressive waves with the same frequency, wavelength p and amplitude in the opposite direction
Define progressive waves (1)
-is a type of wave that Carrie’s energy from one place to another through a medium
Define nodes (1)
Points where the amplitude of the wave is zero
Define anti node (1)
Where the amplitude is maximum
Define monochromatic light (2)
-source of light which have the same frequency and wavelength
-always in phase
State general ideas about the single slit diffraction (3)
-the central fridge is twice as wide as each other the outer fringes
-each of the fringes is the same width
-the outer fringes are less intense than the central fringe
Why is monochromatic coherent sources used in diffraction (3)
-needed to view fringes with different wavelengths or to see young’s fringes clearer
-so you get the same diffraction
-longer wavelengths bend more
Define central maximum (2)
-it is the point with the greatest intensity
-central maximum is the result of waves from all the slits aligning at a certain angle due to constructive interference
Why is the central maximum the brightest (2)
-intensity of light is highest at the centre
-increase in intensity means an increase in number of photons emitted per second
What happens if wavelength increases, state in terms of intensity and diffraction (2)
-increases amount of diffraction
-central maximum is lowered
What happens if slit width increases, state in terms of intensity and diffraction (2)
-decreases amount of diffraction
-intensity of central maximum is higher
What happens if slide width is narrower , state in terms of intensity and diffraction (1)
-makes the fringes wider
State the formula involving angle at which wave forms (1)
n x wavelength = slit spacing x sinO
Define white light (2)
-it is a mixture of different colors
-each having different wavelengths
What is observed when white light is shone through a single slit (2)
-all of the different wavelengths are different by different amounts
-red diffracting the most and it has the greatest wavelength but lowest frequency
What color is the central maximum when white source is used and why (2)
-it’s white
-because it results from the combination of all the colors in the white light spectra
State the formula for fringe spacing (1)
Fringe spacing = ( distance from slit to screen x wavelength ) / spacing between slits
Define and explain constructive interference (5)
-when the wave pulses combine, the resulting pulses have an amplitude equal to the sum of the amplitude of the individual pulses
-Crest + crest gives a bigger crest
-when they are perfectly aligned together they are in phase
- path difference = wave1 - wave2 = whole number of wavelength
-when they’re out of phase path difference is decimals
Define path difference (1)
-distance travelled by the 2 waves from their source to the point where they meet
State and explain the concept of destructive interference (5)
-when 2 or more waves come together and their individual pulses combine in a way that reduces or cancels out their amplitudes
-crest + trough of equal size gives us nothing as 2 displacements cancel out each other
-they are in anitphase
- path difference = wave1 - wave2 = decimal wavelength
-when they’re out of phase the path difference is a whole number
State an application of destructive interference when in phase (2)
-noise canceling earphones
-the headphones cancel out the sound by sending in their own sound by opposite phase which cancels out the noise effect
