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Yellow light (lambda=6000Å) illuminates a single slit of width 1xx10^(-4)m. Calculate : (i) the distance between the two dark lines on either side of the central maximum, when the diffraction pattern is viewed on a screen kept 1.5m away from the slit, (ii) the angular spread of the first diffraction minimum. |
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Answer» Solution :(i) Here, `lambad=6000Å=6xx10^(-7)m` `a=1xx10^(-4)m`, `D=1.5m` ANGULAR SEPARATION of two dark bands on each side of CENTRAL bright band, `2theta=(2lambda)/(a)` and ACTUAL distance between them, `2x=(2lambda)/(a)xxD` `=(2xx6xx10^(-7)xx1.5)/(1xx10^(-4))` `=1.8xx10^(-2)m` `(ii)` For first minimum, `(sintheta~~theta)` `theta=(lambda)/(a)=(6xx10^(-7))/(1xx10^(-4))` `=6xx10^(-3)` rad. |
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