The fringe width is 3.5 mm in Young's double slits experiment for a light of wavelength 700 nm. The fringe width for a light of wavelength 500 mm is:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 2.5 mm
The fringe width (β) is -
$β=\frac{λD}{d}$
$⇒\frac{β_2}{β_1}=\frac{λ_2}{λ_1}$
$⇒\frac{β_2}{3.5}=\frac{500}{700}$
$⇒β_2=3.5×\frac{500}{700}=2.5mm$