Waves Flashcards
A1 mocks
What is the time period?
Time taken for a particle to complete one wave cycle
How do polaroid sunglasses reduce glare?
Light is partially polarised when reflects off reflective surface and sunglasses block out the light in this direction. It lets through light in all other directions therefore reducing glare withput reducing visibility
How so you calculate amplitude in constructive interference?
You add the amplitudes at that point
How is the frequency of the 3rd harmonic related to the first?
3rd harmonic is 3× the first harmonic’s frequency
How do you use microwaves to demonstrate standing waves?
Reflect beam on metal plate
Find nodes and antinodes as you move a probe along perpendicular to metal plate
How do you demonstrate standing waves using speakers?
Lay poweder along glass tube
Loudspeaker waves are reflected
Powder shakes away from antinodes to gather at the nodes
How do you find the speed of sound from the speaker demonstration?
Node to node= half a wavelength
Use frequency from speaker
Why do harmonics form?
An exact number of waves are produced in the time taken for a wave to get to the emd of the string and back again
What does increasing the slit do?
Less diffraction
Central maximum is thinner and intensity is higher
What does increasing the wavelength do?
More diffraction
Wider maximums
Lower intensity
What occurs at bright fringes?
Constructive interference
What occurs at dark spots?
Destructive interference
What must you have to produce a clear, standard 2 source interference pattern?
Both light sources must be coherent
What is path difference?
The amount by which the path travellled by one wave is longer than the path travelled by the other
What do you always include in ‘describe the experiment’ questions?
The graph you plot
