Optics Question 221
Question: A beam of light of wavelength 600 nm from a distant source falls on a single slit 1 mm wide and the resulting diffraction pattern is observed on a screen 2 m away. The distance between the first dark fringes on either side of the central bright fringe is
[IIT-JEE 1994; KCET 2004]
Options:
A) 1.2 mm
B) 1.2 cm
C) 2.4 cm
D) 2.4 mm
Show Answer
Answer:
Correct Answer: D
Solution:
Distance between the first dark fringes on either side of central maxima = width of central maxima = $ \frac{2\lambda D}{d} $ = $ \frac{2\times 600\times {{10}^{-9}}\times 2}{1\times {{10}^{-3}}} $ = 2.4 mm.
