1.

A slit of width d is placedin front of a lens of focal length 0.5 m and is illuminated normally with light of wavelength 5.89 xx 10^(-7)m. The first diffraction minima on either side of the central max. Are separated by 2 xx 10^(-3)m. The width of the slit is :

Answer»

`1.47 xx 10^(-4)` m
`2.29 xx 10^(-4)` m
`1.47 xx 10^(-7)` m
`2.29 xx 10^(-7)m`

Solution :WIDTH of central max. = separation between first min. On EITHER SIDE of central max.
`2theta = (2lambda)/(d)`
LINEAR width `2y = 2((lambda)/(d))f`" `[because (lambda)/(d) = theta]`
`therefore d = (2lambda.f)/(2y) = 2.92 xx 10^(-4)m`.


Discussion

No Comment Found

Related InterviewSolutions