Question

A slit of width a is illuminated by red light of wavelength $6500 \AA$. If the first minimum falls at θ = 30°, the value of a is
(a) 6.5 × 10⁻⁴ mm
(b) 1.3 micron
(c) $3250 \AA$
(d) 2.6 × 10⁻⁴ cm

Answer 1

hey mate I think it's correct answer is part (c)

hope it helps

Answer 2

Heya mate....

here is your answer

Option D

Hope It Helps You ‍❤️‍‍