Find The· Nature of Illumination at the Point If Wavelength of Light is 4000a. - Physics

Advertisements
Advertisements

A point is situated at 7cm and 7·2 cm from two coherent sources. Find the· nature of illumination at the point if wavelength of light is 4000A.

Advertisements

Solution

Path difference = 7.2 cm – 7 cm = 0.2 cm

`"Path diffrence "/lambda=0.2/(4000xx10^-8)=5000`

path difference is integral multiple ofλ

∴ It is bright point

  Is there an error in this question or solution?
2012-2013 (March)

APPEARS IN

RELATED QUESTIONS

What is 'diffraction of light'


In a single slit diffraction pattern, the distance between first minima on the right and first minima on the left of central maximum is 4 mm. The screen on which the pattern is displaced, is 2m from the slit and wavelength of light used is 6000Å. Calculate width of the slit and width of the central maximum.


In the diffraction pattern due to a single slit of width 'd' with incident light of wavelength 'λ', at an angle of  diffraction θ. the condition for first minimum is ....

(a)`lambda sin theta =d`

(b) `d costheta =lambda`

(c)`d sintheta=lambda`

(d) `lambda cos theta=d`


Explain why the maxima at `theta=(n+1/2)lambda/a` become weaker and weaker with increasing n


For a single slit of width "a", the first minimum of the interference pattern of a monochromatic light of wavelength λ occurs at an angle of λa. At the same angle of λa, we get a maximum for two narrow slits separated by a distance "a". Explain.


Two wavelengths of sodium light of 590 nm and 596 nm are used in turn to study the diffraction taking place at a single slit of aperture 2 × 10−6 m. The distance between the slit and the screen is 1·5 m. Calculate the separation between the positions of first maxima of the diffraction pattern obtained in the two cases.


Explain two types of diffraction of light.


In Fraunhofer diffraction, how is the angular width of the central bright fringe affected when slit separation is increased?


Show graphically the intensity distribution in Fraunhofer's single slit diffraction experiment. Label the axes.


Draw the intensity distribution for the diffraction bands produced due to single slit ?


Monochromatic light of wavelength 4300 Å falls on a slit of width ‘a’. For what value of ‘a’ the first maximum falls at 30° ?


In Fraunhofer diffraction, what kind of a source of light is used and where is it situated?


In a single slit diffraction experiment, how does the angular width of the central maxima change when:

  1. screen is moved away from the plane of the slit?
  2. width of the slit is increased?
  3. light of larger wavelength is used?

What should be the order of obstacle or aperture for diffraction of light?


Wavelength of light of frequency 100 Hz is


The penetration of light into the region of geomaterial shadow is called.


The magnifying power of a telescope in normal adjustment is 24, when the length of the telescope tube 1 meter. The focal length of the eye lens is


Diffraction effects are easy to notice in the case of sound waves than in case of light waves because


Direction of the first secondary maximum in the Fraunhoffer diffraction pattern at a single slit is given by (a is the width of the slit):


Which of the following device is used to study the spectra of light?


Consider the diffraction pattern for a small pinhole. As the size of the hole is increased ______.

  1. the size decreases.
  2. the intensity increases.
  3. the size increases.
  4. the intensity decreases.

A polariod (I) is placed in front of a monochromatic source. Another polatiod (II) is placed in front of this polaroid (I) and rotated till no light passes. A third polaroid (III) is now placed in between (I) and (II). In this case, will light emerge from (II). Explain.



AC = CO = D, S1C = S2C = d << D

A small transparent slab containing material of µ = 1.5 is placed along AS2 (Figure). What will be the distance from O of the principal maxima and of the first minima on either side of the principal maxima obtained in the absence of the glass slab?


Draw the graph showing intensity distribution of fringes with phase angle due to diffraction through a single slit. What is the width of the central maximum in comparison to that of a secondary maximum?


Write two points of difference between an interference pattern and a diffraction pattern.


In a diffraction pattern due to a single slit, how will the angular width of the central maximum change, if the screen is moved closer to the slit?

Justify your answer.


In the diagram shown, the separation between the slit is equal to 3λ, where λ is the wavelength of the light incident on the plane of the slits. A thin film of thickness 3λ and refractive index 2 has been placed in the front of the upper slit. The distance of the central maxima on the screen from O is ______.

 


In a single slit Fraunhofer diffraction experiment, how does the angular width of the central maximum change when the slit width is Increased?


Share
Notifications



      Forgot password?
Use app×