Two very narrow slits are spaced 1.8 [itex]\mu[/itex]m apart and are placed 35.0 cm from the screen. What is the distance from the first and second dark lines of the interference pattern when the slits are illuminated with coherent light with [itex]\lambda[/itex] =550 nm(adsbygoogle = window.adsbygoogle || []).push({});

r1-r2=m[itex]\lambda[/itex]

dsin[itex]\theta[/itex]=m[itex]\lambda[/itex]

Rtan[itex]\theta[/itex]=y

Since Im only concerned with the distance i was thinking about just finding the distance between the bright fringes. The problem is I dont know how to get theta.

Ive tried m[itex]\lambda[/itex]=dsin[itex]\theta[/itex] and solved for theta but that didnt work. Im not sure you can find r1 and r2 because the distance between the fringes is missing.

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# Double Slit Experiment without the small angle approximation

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