I'm having trouble getting started with this problem. I know the interference formulas and how it works, but I'm having trouble determining the phase difference.(adsbygoogle = window.adsbygoogle || []).push({});

|----------|------------|

|----------B------------|

|----------|------------|

|----------C------------|

|----------|------------|

A----------|------------O

|----------|------------|

|----------|------------|

|<---x1-->|<-----x2--->|

Consider the above setup, not drawn to scale.

Light of wavelength λ= 475 nm is shined at normal incidence to the first screen with slit A.

The second screen, x1 = 0.7 meters behind the first screen, has two slits, B and C .

The third screen is x2 = 1.5 meters behind the second screen. It has slit O, which is level with slit A. A lightmeter measures the light intensity at the slit O.

When light is sent through slit A and measured at the slit O with either slit B or slit C open one slit at a time, the intensity at the point O is the same: I0 = 0.5 W/m2. (The slit widths can always be adjusted so that this is true, but for this problem you can/should ignore the width of all slits.)

Slit B is at height y1 = 2 mm above slit A.

Slit C is at height y2 = 1 mm above slit A.

Note that the drawing is not drawn to scale.

a) What is the light intensity measured at the point O when both slits B and C are open?

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Two Offset Slits (help really appreciated)

Can you offer guidance or do you also need help?

Draft saved
Draft deleted

**Physics Forums | Science Articles, Homework Help, Discussion**