P&W: Interferenace and diffraction

Question 1

Interference

Answer 1

Provides evidence for the wave nature of light

Question 2

Coherence (Coherent waves)

Answer 2

Coherent waves are waves which have a constant phase relationship.

When two or more waves have the same frequency, speed and wavelength.

Question 3

Completely in Phase Waves

Answer 3

Two waves are completly in phase when the crest of one matches up with the crest of another.

Question 4

Completly out of phase waves

Answer 4

Two waves are completly out of phases when the crest meets up with trough of the other wave.

Question 5

Constructive Interferance

Answer 5

When two waves of equal amplitude meet in phase, they combine to form a wave of twice the amplitude.

Question 6

Destructive Interference

Answer 6

When two waves of equal amplitude meet out of phase, they combine to form a wave of zero amplitude.

Question 7

Maximum/Maxima

Answer 7

A point/points of constructive interferance

Question 8

Minimum/Minima

Answer 8

A point/pouints of destructive interference.

Question 9

Spectra produced using diffraction grating

Answer 9

Central maximum alsways same colour as source
More than one spectra
Red deviated most, violet least.
Spectra is less intense

Question 10

Spectra produced usig a prism.

Answer 10

Only 1 spectrum produced.
Red deviated least, violet deviated the most.
The image is bright.

Question 11

Rough values of different coloured lights

Answer 11

Red 700
Green 550
Blue 500
Violet 400

Question 12

Factors to increase fringe spacing.

Answer 12

Increasng wavelegth
Decreasing the slit separation/ increassing the number of slits.
Increaing the distance between the slits and the screen.