Question
Physics Question on Wave optics
A screen is placed 50cm from a single slit which is illuminated with light of wavelength 6000?. If the distance between the first and third minima in the diffraction pattern is 3.0mm. The width of the slit is
A
1×10−4m
B
2×10−4m
C
0.5×10−4m
D
4×10−4m
Answer
2×10−4m
Explanation
Solution
The position of nth minima in the diffraction pattern is xn=dnDλ ∴x3−x1=(3−1)dDλ =d2Dλ or d=x3−x12Dλ =3×10−32×0.50×6000×10−10 =2×10−4m