A) 640
B) 641
C) 320
D) 321
Correct Answer: B
Solution :
\[d\,sin\,\theta =n\,\lambda \] \[0.320\,\times \,{{10}^{-3}}.\,\sin 30{}^\circ =n.500\,\,\times \,\,{{10}^{-9}}\] \[n\,\,=\,\,\frac{320\,\,\times \,{{10}^{-6}}}{500\,\times \,{{10}^{-9}}}\,\,\times \,\frac{1}{2}\,\,=\,\,\frac{16}{50}\,\times \,1000\,=\,320\] So, total no. of bright fringes \[=\text{ }2\left( 320 \right)+1=641\]You need to login to perform this action.
You will be redirected in
3 sec