Find maxima angle of two interfering waves

[joelkato1605]

Homework Statement

See attached file. (m=0,2,4,6,...)

Relevant Equations

dsin(theta)=m(lambda)

I drew a diagram in the attached files as well, but the the scenario seems to be the same as the double slit experiment, but I don't understand why the answer contains cos instead of sin.

 

[BvU]

Where are the sources in you sketches ?
And the line joining the sources ?
If the screen is normal to the line joining the sources, where is the screen ?

 

[Steve4Physics]

... I don't understand why the answer contains cos instead of sin.

Read the original question carefully. You should see that θ is the angle with respect to the line joining the sources, so the angle you've marked as θ is in fact 90º – θ.

(It's more conventional to define θ in the way you interpreted it, but they've done it differently in this question.)

 

[joelkato1605]

Read the original question carefully. You should see that θ is the angle with respect to the line joining the sources, so the angle you've marked as θ is in fact 90º – θ.

(It's more conventional to define θ in the way you interpreted it, but they've done it differently in this question.)

Oh! Thanks so much I completely missed that.

 

[BvU]

And did you find a

circular interference fringe pattern

on this screen ? Can you make that explicit ?