U2.4.7-2.4.14

Question 1

What is phase difference

Answer 1

The difference in phase of two waves at a point

Question 2

What is path difference

Answer 2

Difference between the distances from two sources to a given point

Question 3

What are the conditions for observable interference

Answer 3

Coherent source

Same or similar amplitude

Question 4

What is the equation for youngs double slit

Answer 4

Lambda = ay / d

Lambda = wavelength
a = slit separation
y = fringe separation
d = distance between slits and screen

Question 5

What is diffraction

Answer 5

The spreading of waves passing through an aperture/opening or passing by an obstacle. Maximum diffraction occurs when the gap width is approximately equal to the wavelength of the wave

Question 6

Diffraction grating equation please

Answer 6

d sin(theta) = n lambda

d = separation of slits of grating spacing
n = diffraction order maximum or order number
Theta = the angle of diffraction where the maximum is observed
Lambda = wavelength