Advertisements
Advertisements
प्रश्न
Answer in brief:
The distance between two consecutive bright fringes in a biprism experiment using the light of wavelength 6000 Å is 0.32 mm by how much will the distance change if light of wavelength 4800 Å is used?
The distance between two bright fringes in a biprism experiment using light of wavelength 6000 A.U. 0.32 mm. By how much will the distance change, if the light of wavelength 4800 A.U. is used?
Advertisements
उत्तर १
Data: λ1 = 6000 Å = 6 × 10-7 m, λ2 = 4800 Å = 4.8 × 10-7 m, W1 = 0.32 mm = 3.2 × 10-4 m
Distance between consecutive bright fringes,
W = `(lambda "D")/"d"`
For `lambda_1, "W"_1 = (lambda_1"D")/"d"` and ...(1)
For `lambda_2, "W"_2 = (lambda_2"D")/"d"` and ...(2)
`"W"_2/"W"_1 = (lambda_2 "D"//"d")/(lambda_1 "D"//"d") = lambda_2/lambda_1`
`therefore "W"_2 = (lambda_2/lambda_1)"W"_1 = ((4.8 xx 10^-7)/(6 xx 10^-7)) (3.2 xx 10^-4)`
`= (0.8)(3.2 xx 10^-4)`m
`= 2.56 xx 10^-4` m
`therefore triangle "W" = "W"_1 - "W"_2`
= 3.2 × 10-4 m - 2.56 × 10-4 m
= 0.64 × 10-4 m
= 6.4 × 10-5 m
= 0.064 mm
उत्तर २
Given:
Distance between consecutive bright fringes,
yA = 0.32 mm = 0.32 × 10-3 m
λA = 6000 A.U. = 6 × 10-7 m, λB = 4800 A.U. = 4.8 × 10-7 m
Let yB be the distance between consecutive bright fringes when wavelength λB is used
To find: Change in distance between the fringes |yA – yB| Formula: yAλB = yBλA
Calculation:
From formula,
∴ yB = `("y"_"A""y"_"B")/(λ_"A") = (0.32 xx 10^-3 xx 4.8 xx 10^-7)/(6 xx 10^-7)`
= 0.256 × 10-3
∴ Change = |yA – yB|
= = |0.320 × 10-3 - 0.256 × 10-3|
= 0.064 × 10-3 m
= 0.064 mm
The change in distance between the fringes is 0.064 mm.
संबंधित प्रश्न
Draw the sketches to differentiate between plane wavefront and spherical wavefront.
Define a wavefront.
If we put a cardboard (say 20 cm × 20 cm) between a light source and our eyes, we can't see the light. But when we put the same cardboard between a sound source and out ear, we hear the sound almost clearly. Explain.
Is it necessary to have two waves of equal intensity to study interference pattern? Will there be an effect on clarity if the waves have unequal intensity?
Light is _______________ .
The equation of a light wave is written as \[y = A \sin\left( kx - \omega t \right).\] Here, `y` represents _______ .
An amplitude modulated (AM) radio wave bends appreciably round the corners of a 1 m × 1 m board but a frequency modulated (FM) wave only bends negligibly. If the average wavelengths of the AM and FM waves are \[\lambda_a and \lambda_f,\]
A light wave can travel
(a) in vacuum
(b) in vacuum only
(c) in a material medium
(d) in a material medium only
When light propagates in vacuum, there is an electric field as well as a magnetic field. These fields ____________ .
(a) are constant in time
(b) have zero average value
(c) are perpendicular to the direction of propagation of light.
(d) are mutually perpendicular
Three observers A, B and C measure the speed of light coming from a source to be νA, νBand νC. A moves towards the source and C moves away from the source at the same speed. B remains stationary. The surrounding space is water everywhere.
(a) \[\nu_A > \nu_B > \nu_C\]
(b) \[\nu_A < \nu_B < \nu_C\]
(c) \[\nu_A = \nu_B = \nu_C\]
(d) \[\nu_B = \frac{1}{2}\left( \nu_A + \nu_C \right)\]
Find the range of frequency of light that is visible to an average human being
\[\left( 400\text{ nm }< \lambda < 700\text{ nm}\right)\]
Plane microwaves are incident on a long slit of width 5.0 cm. Calculate the wavelength of the microwaves if the first diffraction minimum is formed at θ = 30°.
Answer in brief:
In a double-slit arrangement, the slits are separated by a distance equal to 100 times the wavelength of the light passing through the slits.
- What is the angular separation in radians between the central maximum and an adjacent maximum?
- What is the distance between these maxima on a screen 50.0 cm from the slits?
White light consists of wavelengths from 400 nm to 700 nm. What will be the wavelength range seen when white light is passed through a glass of refractive index 1.55?
Monochromatic electromagnetic radiation from a distant source passes through a slit. The diffraction pattern is observed on a screen 2.50 m from the slit. If the width of the central maximum is 6.00 mm, what is the slit width if the wavelength is
(a) 500 nm (visible light)
(b) 50 µm (infrared radiation)
(c) 0.500 nm (X rays)?
When light travels from an optically rarer medium to an optically denser medium, the speed decreases because of change in ______
The path difference between two waves meeting at a point is (11/4)λ. The phase difference between the two waves is ______
What is the relation between phase difference and Optical path in terms of speed of light in a vacuum?
State any four conditions for obtaining well–defined and Steady interference patterns.
Two vectors of the same magnitude have a resultant equal to either of the two vectors. The angle between two vectors is
Emission and absorption is best described by ______.
A ray is an imaginary line ______.
Light appears to travel in straight lines since
Light emerges out of a convex lens when a source of light kept at its focus. The shape of wavefront of the light is ______.
