Question

Monochromatic green light of wavelength $5 \times 10^{-7} m$ illuminates a pair of slits $1 mm$ apart. The separation of bright lines on the interference pattern formed on a screen $2 m$ away is:

• A. $0.25 \,mm$
• B. $0.1\,mm$
• C. $1 \,mm$
• D. $0.01 \,mm$

Answer 1

Answer: (C)

$\beta=\frac{\lambda D }{ d }=\frac{5 \times 10^{-7} \times 2}{10^{-3}}=10^{-3} m$
$\beta=1 \,mm$