In a Young's double slit experiment, a laser light of 560 nm produces an interference pattern with consecutive bright fringes' separation of 7.2 mm. Now another light is used to produce an interference pattern with consecutive bright fringes' separation of 8.1 mm. The wavelength of second light is __________ nm.
Answer (integer)
630
Solution
<p>$\lambda = 560 \times {10^{ - 9}}$</p>
<p>${B_1} = 7.2 \times {10^{ - 3}}$</p>
<p>${B_2} = 8.1 \times {10^{ - 3}}$</p>
<p>${{{B_1}} \over {{B_2}}} = {{{\lambda _1}} \over {{\lambda _2}}}$</p>
<p>$$ \Rightarrow {\lambda _2} = {{560 \times {{10}^{ - 9}} \times 8.1 \times {{10}^{ - 3}}} \over {7.2 \times {{10}^{ - 3}}}}$$</p>
<p>$= 6.3 \times {10^{ - 7}}$ m</p>
<p>$= 630$ nm</p>
About this question
Subject: Physics · Chapter: Optics · Topic: Reflection and Mirrors
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