# Young's slit experiment question Help me

1. Oct 19, 2004

### saltrock

Young's slit experiment question!!!Help me

On a young's slit experiment,i found that,even at the maxima,the wave intensity was small.If i had made the slit wider to let more energy through,would the wave intensity be brighter at maxima?If not why?

2. Oct 19, 2004

### Claude Bile

Yes, the irradiance (and the intensity) would be greater because the light is diffracting over a smaller angle.

Note that the units for intensity are W/Steradian, the units for irradiance are W/m^2. I suspect you are actually referring to irradiance.

Claude.

3. Oct 20, 2004

### saltrock

I think if i made the slit wider,

>that means the diffraction is less
>less diffraction=less interference
>which means the intensity (brightneess)decreases.

Correct me if i am wrong please!!!

4. Oct 20, 2004

### Vector Sum

You are sort of correct by say "diffraction is less," if you mean that the beam is less spread out. If the slit is widened, the path of the photons would become less uncertain, meaning the photon concentration that falls on the central maxima will be greater. This means greater intensity.

5. Oct 20, 2004

### Claude Bile

What do you mean by 'less interference'?

Claude.