# In a double-slit experiment using the light of wavelength 600 nm, the angular width of the fringe formed on a distant screen is 0.1°. Find the spacing between the two slits.? - Physics

Numerical

In a double-slit experiment using the light of wavelength 600 nm, the angular width of the fringe formed on a distant screen is 0.1°. Find the spacing between the two slits.?

#### Solution 1

Angular width (θ) of fringe in double-slit experiment is given by

theta=lambda/"d"

Where

d = Spacing between the slits

Given:

Wavelength of light, λ = 600 nm

Angular width of fringe

θ = 0.1° = pi/1800 = 0.0018 rad

∴ d = lambda/theta

d = (600xx10^(-9))/(18xx10^(-4))

d = 0.33 × 103 m

#### Solution 2

Wavelength of light used, λ = 6000 nm = 600 × 10−9 m

Angular width of fringe, θ = 0.1° = 0.1 xx pi/180 = 3.14/1800 "rad"

Angular width of a fringe is related to slit spacing (d) as:

θ = lambda/"d"

"d"= lambda/θ

= (600 xx 10^(-9))/(3.14 /1800)

= 3.44 × 104 m

Therefore, the spacing between the slits is 3.44 × 104 m.

Concept: Interference of Light Waves and Young’S Experiment
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#### APPEARS IN

NCERT Class 12 Physics Textbook
Chapter 10 Wave Optics
Q 16 | Page 384
NCERT Physics Part 1 and 2 Class 12
Chapter 10 Wave Optics
Exercise | Q 10.16 | Page 384

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