Consider sunlight incident on a slit of width 10 4 Å. The image seen through the slit shall
(a) Be a fine sharp slit white in colour at the centre
(b) A bright slit white at the centre diffusing to zero intensities at the edges
(c) A bright slit white at the centre diffusing to regions of different colours
(d) Only be diffused slit white in colour.
Consider sunlight incident on a slit of width 10 4 Å. The image seen through the slit shall
(a) Be a fine sharp slit white in colour at the centre
(b) A bright slit white at the centre diffusing to zero intensities at the edges
(c) A bright slit white at the centre diffusing to regions of different colours
(d) Only be diffused slit white in colour.
-
1 Answer
-
This is a Multiple Choice Questions as classified in NCERT Exemplar
Answer- ( a)
Explanation- given width of slit is 10410-10m= 10-6
Wavelength of sunlight varies from 4000A0 to 8000A0
As the width of slit is comparable to that of wavelength, hence diffraction occurs with maxima at centre. So, at the centre all colours appear i.e., mixing of colours form white patch at the centre.
Similar Questions for you
At lower end
Tension, T? = 2g = 20 N (due to the 2 kg block)
Velocity, v? = √ (T? /μ) = √ (20/μ)
Wavelength, λ? = 6 cm
At upper end
Tension, T? = (2 kg + 6 kg)g = 8g = 80 N (due to the block and the rope)
Velocity, v? = √ (T? /μ) = √ (80/μ) = √4 * √ (20/μ) = 2v?
Since frequency (f) remains the same:
f = v? /λ? = v? /λ?
⇒ λ? = λ? * (v? /v? )
⇒ λ? = λ? * (2v? /v? ) = 2λ?
⇒ λ? = 2 * 6 cm = 12 cm
β = λD / (d? + a? sinωt)
β? - β? = λD/ (d? - a? ) - λD/ (d? + a? )
= λD [ (d? + a? ) - (d? - a? ) / (d? ² - a? ²) ]
= 2λDa? / (d? ² - a? ²)
3d = 0.6mm
D = 80cm
= 800mm
Path difference is given by
BP – Andhra Pradesh = Dx
[for Dark fringe at P]
n = 0, for first dark fringe
first dark fringe is observed on the screen directly opposite to one of the slits]
The distance between two successive bright fringes is fringe width .
Taking an Exam? Selecting a College?
Get authentic answers from experts, students and alumni that you won't find anywhere else
Sign Up on ShikshaOn Shiksha, get access to
- 65k Colleges
- 1.2k Exams
- 687k Reviews
- 1800k Answers