A) 0.2 cm
B) 0.24 cm
C) 2.4 cm
D) 0.024 cm
Correct Answer: A
Solution :
Using the relation for fringe width is. \[\beta =\frac{\lambda D}{d}\] or \[d=\frac{\lambda D}{\beta }\] ??.(1) Here, \[\lambda =60000\overset{\text{o}}{\mathop{\text{A}}}\,=6000\times {{10}^{-8}}cm,\] \[D=40cm,\,\,\beta =0.012\] From equation (1) after putting the values we get So, \[d=\frac{6000\times {{10}^{-8}}\times 40}{0.012}\] \[=0.2cm\]You need to login to perform this action.
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