Diffraction and interference

Question 1

Narrow gap causes ……. amount of bending of the waves

Answer 1

Greater

Question 2

Wider gap causes ….. amount of bending of the waves

Answer 2

Lower

Question 3

Shorter wavelength causes…. diffraction

Answer 3

Less

Question 4

Longer wavelength causes ….. diffraction

Answer 4

More

Question 5

Coherent waves

Answer 5

Waves with the same frequency, wavelength and velocity

Have a constant phase difference

Question 6

Interference

Answer 6

Caused when coherent waves overlap

Question 7

Path difference

Answer 7

The distance between slits emitting waves

Question 8

Constructive interference

Answer 8

When both crest and trough meet to produce a wave of greater amplitude

Question 9

Constructive interference equation maxima

Answer 9

Path difference = m lambda
Where path difference = distance between slits
m = number of complete wavelengths in path difference
lambda = wavelength

Question 10

Destructive interference

Answer 10

Crests meets trough on different coherent waves to produce a wave of lesser amplitude

Question 11

Path difference equation minima

Answer 11

path difference = (m+1/2) lambda

Question 12

d=

Answer 12

distances between adjacent slits

Question 13

D=

Answer 13

distances from grating to wall

Question 14

Grating equation

Answer 14

dsinØ = m lambda
Where
d = distance between adjacent gratings
Ø = angle of right angled triangle obtained from grating - m=0, m=x between m=0 and m=x

Question 15

How to get Ø

Answer 15

Find D, distance from grating to wall, and L, distance from m = 0 to m=x then input into tanØ = L/D