Advertisements
Advertisements
प्रश्न
Estimate the distance for which ray optics is good approximation for an aperture of 4 mm and wavelength 400 nm.
Advertisements
उत्तर
Fresnel’s distance (ZF) is the distance for which the ray optics is a good approximation. It is given by the relation,
`"Z"_"F" = "a"^2/lambda`
Where,
Aperture width, a = 4 mm = 4 ×10−3 m
Wavelength of light, λ = 400 nm = 400 × 10−9 m
`"Z"_"F" = (4 xx 10^(-3))^2/(400 xx 10^(-9))`
= 40 m
Therefore, the distance for which the ray optics is a good approximation is 40 m.
APPEARS IN
संबंधित प्रश्न
In a single slit diffraction experiment, the width of the slit is made double the original width. How does this affect the size and intensity of the central diffraction band?
Two students are separated by a 7 m partition wall in a room 10 m high. If both light and sound waves can bend around obstacles, how is it that the students are unable to see each other even though they can converse easily?
In a single slit diffraction experiment, when tiny circular obstacle is placed in path of light from a distance source, a bright spot is seen at the centre of the shadow of the obstacle. Explain why?
Will the diffraction effects from a slit be more or less clearly visible if the slit-width is increased?
In a single slit diffraction experiment, the width of the slit is increased. How will the
- size and
- intensity
of central bright band be affected? Justify your answer.
What is diffraction when light passes through a single narrow slit?
What are LN and M in the single-slit experimental setup?
Which point on the screen lies along the normal to the slit?
How is point P located in the single-slit experimental setup?
What separates the bright regions in a single-slit diffraction pattern?
Why is point C the brightest point of the single-slit diffraction pattern?
What path difference between corresponding rays from the two equal halves of the slit causes them to cancel?
What is the path difference between rays from the top and middle of a slit of width \[a\]?
Into how many equal parts can the slit be divided to generalise the condition for minima?
Why are secondary maxima much weaker than the central maximum?
