What phenomenon provides evidence that light is made up of photons?
The photoelectric effect
What is produced when two waves of equal amplitude meet in phase?
Constructive interference
What happens when two waves of equal amplitude meet out of phase?
Destructive interference
How can interference be demonstrated with water waves?
Using a ripple tank with two dippers creating waves
What is constructive interference?
Waves arriving at the same point in phase, causing an increase in amplitude
What is destructive interference?
Waves arriving out of phase, causing cancellation of the wave
What is required for light interference in Young’s double slit experiment?
Two coherent light sources
What is monochromatic light?
Light that contains only one wavelength
What do interference fringes consist of?
Bands of bright light (constructive interference) and dark bands (destructive interference)
What is the significance of path difference in sound wave interference?
It determines whether constructive or destructive interference occurs
What is the path difference condition for constructive interference?
Path difference = nλ, where n is a whole number
What is the path difference condition for destructive interference?
Path difference = (n + ½)λ, where n is a whole number
What experimental setup demonstrates microwave interference?
A double slit with a microwave transmitter and receiver
How does a grating produce interference patterns?
By having many slits close together that create coherent waves
What is the formula relating fringe order, wavelength, and slit separation?
mλ = d sinθ, where m is the order of fringe, λ is wavelength, d is slit separation, and θ is angle of deviation
What is the central maximum in a grating experiment?
The brightest fringe at the center, where all wavelengths are in phase
What happens to the colors in a spectrum produced by white light in a grating?
Red is always to the outside and violet to the inside due to differing wavelengths
What is the effect of moving a metal plate in a microwave interference setup?
It changes the path difference, affecting whether constructive or destructive interference occurs
What is the result of a path difference of 1½λ in sound wave interference?
Destructive interference occurs, producing a minimum sound level
What is the role of coherent sources in wave interference?
They ensure that waves have the same frequency, wavelength, and phase relationship
What does the term ‘fringe separation’ refer to?
The distance between successive interference fringes on a screen
What is the effect of using a laser in a grating experiment?
It produces especially clear and sharp interference fringes
What is the significance of the first order maximum in interference?
It is the first point where constructive interference occurs after the central maximum
What happens to fringe brightness as you move further from the center in a spectrum?
Fringes become less bright and more spread out
