Answer:
Explanation:
slit width d = .695 x 10⁻³ m
screen distance D = 2.16 m
distance of first minima x = 1.35 x 10⁻³ m
Let wave length of light used be λ
distance of first minima x = λ D / d
putting the values
1.35 x 10⁻³ = λ x 2.16 / .695 x 10⁻³
λ = .4343 x 10⁻⁶ m
= 434.3 x 10⁻⁹ m
= 434.3 nm .