Class 12 Exam  >  Class 12 Questions  >  A parallel beam of light of wavelength 500 nm... Start Learning for Free
A parallel beam of light of wavelength 500 nm falls on a narrow slit and the resulting diffraction pattern is observed on a screen 1 m away. It is observed that the first minimum is at a distance of 2.5 mm from the centre of the screen. Find the width of the slit.
  • a)
    0.32 mm
  • b)
    0.2 mm
  • c)
    0.3 mm
  • d)
    0.25 mm
Correct answer is option 'B'. Can you explain this answer?
Verified Answer
A parallel beam of light of wavelength 500 nm falls on a narrow slit a...
Wavelength of light beam, λ
Distance of the screen from the slit, D=1m
For first minima, n=1
Distance between the slits is d
Distance of the first minimum from the centre of the screen can be obtained as, x = 2.5mm = 2.5×10−3
Now, nλ = xd/D
⇒ d= nλD/x = 0.2mm
Therefore, the width of the slits is 0.2 mm.
View all questions of this test
Most Upvoted Answer
A parallel beam of light of wavelength 500 nm falls on a narrow slit a...
Given:
Wavelength of light, λ = 500 nm = 500 × 10⁻⁹ m
Distance of screen from the slit, D = 1 m
Distance of first minimum from the centre of the screen, x = 2.5 mm = 2.5 × 10⁻³ m

To find: Width of the slit, a

Formula used:
The position of the nth minimum (on either side of the central bright fringe) is given by,
a sin θ = nλ
where,
a = width of the slit
n = order of diffraction minimum
λ = wavelength of light
θ = angle of diffraction (small angle approximation)

Calculation:
We know that for the first minimum, n = 1.
Using the small angle approximation, we can write sin θ ≈ θ, where θ is in radians.
Therefore, aθ = nλ
θ = x/D [Distance of first minimum from the centre of the screen = Distance of the screen from the slit × tan(θ)]
∴ a = nλθ [Substituting the value of θ]
a = (1)(500 × 10⁻⁹)(2.5 × 10⁻³)/(1)
a = 1.25 × 10⁻⁶ m = 0.125 mm

Therefore, the width of the slit is 0.2 mm (approx).

Hence, option (b) is the correct answer.
Explore Courses for Class 12 exam

Similar Class 12 Doubts

A parallel beam of light of wavelength 500 nm falls on a narrow slit and the resulting diffraction pattern is observed on a screen 1 m away. It is observed that the first minimum is at a distance of 2.5 mm from the centre of the screen. Find the width of the slit.a)0.32 mmb)0.2 mmc)0.3 mmd)0.25 mmCorrect answer is option 'B'. Can you explain this answer?
Question Description
A parallel beam of light of wavelength 500 nm falls on a narrow slit and the resulting diffraction pattern is observed on a screen 1 m away. It is observed that the first minimum is at a distance of 2.5 mm from the centre of the screen. Find the width of the slit.a)0.32 mmb)0.2 mmc)0.3 mmd)0.25 mmCorrect answer is option 'B'. Can you explain this answer? for Class 12 2024 is part of Class 12 preparation. The Question and answers have been prepared according to the Class 12 exam syllabus. Information about A parallel beam of light of wavelength 500 nm falls on a narrow slit and the resulting diffraction pattern is observed on a screen 1 m away. It is observed that the first minimum is at a distance of 2.5 mm from the centre of the screen. Find the width of the slit.a)0.32 mmb)0.2 mmc)0.3 mmd)0.25 mmCorrect answer is option 'B'. Can you explain this answer? covers all topics & solutions for Class 12 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A parallel beam of light of wavelength 500 nm falls on a narrow slit and the resulting diffraction pattern is observed on a screen 1 m away. It is observed that the first minimum is at a distance of 2.5 mm from the centre of the screen. Find the width of the slit.a)0.32 mmb)0.2 mmc)0.3 mmd)0.25 mmCorrect answer is option 'B'. Can you explain this answer?.
Solutions for A parallel beam of light of wavelength 500 nm falls on a narrow slit and the resulting diffraction pattern is observed on a screen 1 m away. It is observed that the first minimum is at a distance of 2.5 mm from the centre of the screen. Find the width of the slit.a)0.32 mmb)0.2 mmc)0.3 mmd)0.25 mmCorrect answer is option 'B'. Can you explain this answer? in English & in Hindi are available as part of our courses for Class 12. Download more important topics, notes, lectures and mock test series for Class 12 Exam by signing up for free.
Here you can find the meaning of A parallel beam of light of wavelength 500 nm falls on a narrow slit and the resulting diffraction pattern is observed on a screen 1 m away. It is observed that the first minimum is at a distance of 2.5 mm from the centre of the screen. Find the width of the slit.a)0.32 mmb)0.2 mmc)0.3 mmd)0.25 mmCorrect answer is option 'B'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of A parallel beam of light of wavelength 500 nm falls on a narrow slit and the resulting diffraction pattern is observed on a screen 1 m away. It is observed that the first minimum is at a distance of 2.5 mm from the centre of the screen. Find the width of the slit.a)0.32 mmb)0.2 mmc)0.3 mmd)0.25 mmCorrect answer is option 'B'. Can you explain this answer?, a detailed solution for A parallel beam of light of wavelength 500 nm falls on a narrow slit and the resulting diffraction pattern is observed on a screen 1 m away. It is observed that the first minimum is at a distance of 2.5 mm from the centre of the screen. Find the width of the slit.a)0.32 mmb)0.2 mmc)0.3 mmd)0.25 mmCorrect answer is option 'B'. Can you explain this answer? has been provided alongside types of A parallel beam of light of wavelength 500 nm falls on a narrow slit and the resulting diffraction pattern is observed on a screen 1 m away. It is observed that the first minimum is at a distance of 2.5 mm from the centre of the screen. Find the width of the slit.a)0.32 mmb)0.2 mmc)0.3 mmd)0.25 mmCorrect answer is option 'B'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice A parallel beam of light of wavelength 500 nm falls on a narrow slit and the resulting diffraction pattern is observed on a screen 1 m away. It is observed that the first minimum is at a distance of 2.5 mm from the centre of the screen. Find the width of the slit.a)0.32 mmb)0.2 mmc)0.3 mmd)0.25 mmCorrect answer is option 'B'. Can you explain this answer? tests, examples and also practice Class 12 tests.
Explore Courses for Class 12 exam
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev