What is the refractive index of water relative to air?
Click to see answer
4/3.
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What is the refractive index of water relative to air?
4/3.
What is a spherical wavefront?
It is formed by a point source of light, such as a small electric bulb illuminating a dark room.
What is the distance from the slit to the screen in the diffraction experiment?
1 meter.
What principle is used to prove the laws of reflection?
Huygens Principle.
What is the wavelength of the light used in the experiment?
500 nm.
If two waves have intensities in the ratio of 9:1, what is the ratio of intensity of maxima to that of minima?
10:1.
What is the wavelength of light used in the double slit experiment?
600 nm.
What is the shape of the wave fronts after passing through a convex lens from a point source at its focus?
The wave fronts become planar (parallel) as they exit the lens.
What is the primary focus of the provided links?
They focus on concepts related to waves and wave interference.
Why is no interference pattern observed when two coherent sources are far apart from each other?
The path difference becomes too large, causing the waves to be out of phase and resulting in a lack of observable interference.
What is sound wave interference?
The phenomenon that occurs when two or more sound waves overlap and combine.
What happens to sound waves when they pass through a narrow opening?
They diffract.
At what angle is the ray of light incident on the water-glass interface?
30 degrees.
What is a wavefront?
The locus of all points in the field of an optical disturbance having the same phase at a given instant.
What educational resource is mentioned for learning about waves?
Ophysics.com.
What effect does replacing blue light with sodium light have on the interference fringes in Young's double slit experiment?
The interference fringes will become closer together due to the longer wavelength of sodium light.
What are the two types of sound wave interference?
Constructive interference and destructive interference.
What causes the slight shaking of the picture on the television screen in Paro when a low flying aircraft passes overhead?
The disturbance of the signals is likely due to the aircraft's sound waves or pressure changes affecting the air.
What affects the shape of a wavefront?
The nature of the source of light.
Why is no interference pattern observed when two coherent sources are infinitely close to each other?
The waves from the sources overlap too much, leading to a uniform intensity without distinct interference fringes.
What are the possible phase differences mentioned in the question?
90 °, 0 °, 180 °, or Cannot be determined.
What is a key characteristic of particles on a wavefront?
All the particles on it are in the same phase.
What can emerge when two waves interfere?
Many different superposition patterns.
In which direction does a wave propagate relative to the wavefront?
In the direction perpendicular to the wavefront.
What type of simulation can be found on the PHET website?
Wave interference simulations.
What is the phase difference between two waves if they interfere as shown in the figure?
Cannot be determined.
What happens to wave fronts when a point source of light is placed at the focus of a convex lens?
The wave fronts emerge as parallel lines after passing through the lens.
What is the role of a convex lens in relation to wave fronts from a point source?
A convex lens converges wave fronts from a point source into parallel lines.
How do interference and diffraction differ based on intensity patterns?
Interference produces a series of bright and dark fringes, while diffraction results in a gradual variation in intensity without distinct fringes.
What is a ray in the context of wave propagation?
A ray is an imaginary line that represents the direction of energy propagation in a wave.
What is the formula for resultant amplitude (A) in terms of individual amplitudes (a1 and a2)?
A = √(a1² + a2² + 2a1a2 cos(φ))
How does increasing the distance between the slits affect the angular separation of interference fringes in Young's experiment?
The angular separation decreases.
What happens to the interference fringes in Young's double slit experiment if the screen is closer to the slits?
The interference fringes will become wider.
What is the formula for the angular position of the nth maxima?
sin(θ_n) = nλ/d, where n = 0, 1, 2, 3,...
What is a wave?
A disturbance that propagates in a medium.
What is a cylindrical wavefront?
It is formed when the source of light is linear, such as a tube light.
What can disperse light into a spectrum in a spectrograph?
A prism or a diffraction grating.
What is the relationship between the distance between fringes (Δy) and the wavelength (λ) in a double slit experiment?
Δy = xλ / d.
What happens to the fringe width when the separation between the slits is halved and the distance to the screen is doubled in Young's double slit experiment?
The fringe width will be doubled.
What is the ratio of the amplitudes of light from two slits in Young’s experiment with widths in the ratio of 1:25?
1:5.
How does light from stars enter a spectrograph?
Through a telescope.
What is the phase difference at the first minimum of a single slit diffraction pattern?
𝜋.
What principle is used to prove Snell's Law of refraction?
Huygens Principle.
What is the relationship established by Huygens Principle for angles of incidence and reflection?
sin(i) = sin(r).
What is a spectrograph used for?
To study the spectra of stars and galaxies.
Which wave will diffract more around a building: radio wave or visible light wave?
Radio wave will diffract more around the building.
What happens to the diffraction pattern when red light is used instead of blue light?
A. Bands become broader and farther apart.
Why is a cheerleader's yell hardly heard in a noisy football ground?
Because sound waves diffract when passing through the narrow opening of the mouth.
What is the alternative formula for the angular position of the nth minima?
sin(θ_n) = (n - 1/2)λ/d, where n = 1, 2, 3,...
What is the wavelength of light used in the diffraction pattern experiment?
500 nm.
For light waves from two coherent sources with intensities in the ratio of 4:9, what is the ratio of intensities of maxima and minima?
13:5.
What is the refractive index of glass relative to air?
3/2.
What is the ratio of amplitudes when the ratio of intensities of two waves is 4:1?
2:1.
What happens to the slit separation in Young's double slit experiment when it is doubled?
The slit separation is doubled.
What are secondary wavelets?
Disturbances created by each point on the primary wavefront that travel in all directions.
What is the wavelength of the laser light used in Pema's double-slit experiment?
632.8 nm.
What is Snell's Law formula for refraction?
μ1 sin(i) = μ2 sin(r).
What is the purpose of a ripple tank?
To show the diffraction and interference of waves.
What is the width of the slit used in the experiment?
0.50 mm.
What is another reason to choose a diffraction grating?
They can separate light into more wavelengths than prisms.
What is the formula for the linear position of the nth maxima from the central maxima?
y = n * (D * λ / d), where n = 0, 1, 2, 3,...
What does Huygens' principle state about points on a primary wavefront?
Each point acts as a source of new disturbances called 'secondary wavelets' that travel in all directions with the velocity of light in the medium.
To maintain the same fringe spacing on the screen after doubling the slit separation, how must the screen to slit distance D be changed?
D must be changed to D/2.
What happens to intensity during destructive interference?
The intensity of light will be minimum, I_min = I1 + I2 - 2√(I1I2).
How do rays and wave fronts relate to each other?
Rays are perpendicular to wave fronts and indicate the direction of wave propagation.
What is the angular width of the 1st bright fringe formed on a distant screen?
0.1°.
At what angle do waves and wavefronts meet?
At 90 degrees.
How can interference of sound waves be observed?
Through phenomena such as beats, where two close frequencies create a fluctuating sound intensity.
What is the formula for the angular position of the nth minima?
sin(θ_n) = (n + 1/2)λ/d, where n = 0, 1, 2, 3,...
What is the formula for the linear position of the nth minima from the central maxima?
y = (n - 1/2) * (D * λ / d), where n = 1, 2, 3,...
What device can be used to offset the diffraction of sound?
A megaphone.
In the context of Huygens Principle, what does sin(i) represent?
The sine of the angle of incidence.
What is the formula for fringe width?
β = (D * λ) / d.
What is the formula for resultant intensity (I) in terms of individual intensities (I1 and I2)?
I = I1 + I2 + 2√(I1I2) cos(φ)
Why do radio waves diffract more than visible light waves?
Because radio waves have longer wavelengths compared to visible light waves.
What is the sine of the angle of refraction when light travels from water to glass?
0.444.
What does the formula relate to in terms of light?
The velocity of light in different media.
What is diffraction of light?
The bending of light around the corners of an obstacle placed in its path.
What is the relationship among intensity (I), slit width (W), and amplitude (a & b)?
Intensity is directly proportional to the square of the amplitude and inversely proportional to the slit width.
What do the symbols μ1 and μ2 represent in Snell's Law?
The refractive indices of the two media.
What do the solid lines in the wave diagram represent?
Crests of the waves.
What is a wave front?
A wave front is a surface over which an oscillation has a constant phase.
What happens to waves when the point of observation is far from the source?
The waves become parallel, resulting in a plane wavefront of light.
What is the distance between two adjacent maxima or minima called?
Fringe width.
What is the correct option for changing the screen to slit distance D to maintain fringe spacing?
A. D/2
What distance was the screen placed from the slits in the double-slit experiment?
1 m.
What happens during constructive interference of sound waves?
The amplitudes of the waves add together, resulting in a louder sound.
At what distance from the central maximum is the first minimum observed?
5 mm.
What is the absolute refractive index of glass?
3/2.
Give an example of a plane wavefront.
Sunlight.
What is the velocity of light in air compared to glass?
The velocity of light in air is greater than in glass.
Can you give an example of a wave front?
A plane wave front is an example where all points on the front are in phase.
In Young's experiment, if the distance between the slit and screen is doubled and the separation is halved, what happens to the fringe width?
The fringe width remains the same.
What occurs when the crest of one wave meets the crest of another wave?
A bright spot called maxima is formed, resulting in constructive interference.
What is formed when a surface touches secondary wavelets tangentially in the forward direction?
A new wavefront known as the secondary wavefront.
What phenomenon is exhibited by the diffraction pattern?
Diffraction.
In the context of Huygens Principle, what does sin(r) represent?
The sine of the angle of reflection.
What is represented by 'v' in the formulas?
The velocity of light in a medium.
What does the diffraction pattern look like when using monochromatic light?
It consists of alternate bright and dark bands of unequal widths.
What does the variable 'd' represent in the context of the double slit experiment?
The distance between the slits.
How can a wavefront be visually represented?
By drawing a surface in a medium where the medium particles are in the same phase of oscillation.
What occurs during destructive interference of sound waves?
The amplitudes of the waves cancel each other out, resulting in a quieter sound or silence.
If the separation between the two slits is doubled and the distance to the screen is halved, how does the fringe width change?
The fringe width increases by four times.
How do you calculate the refractive index of a liquid?
Refractive index = Speed of light in air / Speed of light in the liquid.
How far is the screen placed from the slit in the diffraction experiment?
2 m.
What are coherent sources of light?
Sources that emit continuous light waves with the same wavelength, frequency, and phase or constant phase difference.
What is one advantage of using a diffraction grating over a prism in a spectrograph?
Diffraction gratings can provide higher resolution spectra.
What is the speed of yellow light in the given liquid?
2.4 × 10^8 m/s.
How does a megaphone help in sound transmission?
It allows sound waves to emerge from a much wider opening, reducing flaring.
How does the width of a slit affect diffraction?
The narrower the slit, the greater the diffraction.
What is the speed of light in glass?
2 × 10^8 m/s.
How is the fringe width affected if the separation between the two slits is decreased in Young's double slit experiment?
The fringe width increases.
What is the distance between the two dark bands on either side of the central bright band in the diffraction pattern?
To be calculated based on given parameters.
What are the conditions necessary for obtaining two coherent sources of light?
What are the wavelengths of blue and green light used in Young's double slit experiment?
Blue light: 436 nm, Green light: 546 nm.
What is the distance between the two slits in the interference pattern experiment?
0.4 mm.
What is the role of the diffraction grating in a spectrometer?
It splits the light into its fundamental colors.
Why can we hear a sound source around a corner?
Because diffraction of much longer wavelengths (e.g., sound waves, microwaves) is common.
What is the wavelength of light used in the double slit experiment?
633 nm.
What will be the angular separation of the first order fringe from the central maximum for light of wavelength 500 nm diffracted at a slit of width 0.5 mm?
The angular separation can be calculated using the formula θ = λ / a, where λ is the wavelength and a is the slit width.
What is the formula to calculate the distance between fringes in a double slit experiment?
Distance between fringes = (wavelength × distance to screen) / slit separation.
What is the separation on the screen between the third order bright fringes of the two interference patterns?
To be calculated using the formula for fringe separation.
What is the refractive index of water?
1.3.
What condition allows us to approximate sinθ as θ in the double slit experiment?
For small angles, where θ is in radians.
What happens when the crest of one wave meets the trough of another wave?
They cancel each other, forming a dark spot called minima, resulting in destructive interference.
What is the significance of the secondary wavefront in Huygens' principle?
It represents the new wavefront at any instant formed by the tangential contact of a surface with secondary wavelets.
What is diffraction in the context of water waves?
Diffraction refers to the bending and spreading of water waves when they encounter obstacles or openings.
What is destructive interference?
The phenomenon where a crest from one wave meets a trough from another, resulting in cancellation.
What does the notation v*t represent in the context of wave reflection?
It represents the product of wave velocity and time.
How far is the screen from the slits in Young's double slit experiment?
1.0 m.
What is the phase difference for the third bright fringe in Young's experiment?
The phase difference is 6π radians.
What are examples of incoherent sources of light?
Incandescent light bulbs and fluorescent lamps.
What is the path difference for the third bright fringe in Young's experiment?
The path difference is 3λ (3 times the wavelength).
What happens to the interference pattern if one of the two slits in Young's double slit experiment is closed?
A. The interference fringes disappear.
Which method is more commonly used in astronomical spectrographs?
Diffraction gratings.
Name some examples of diffraction we see in daily life.
Examples include the spreading of sound waves, patterns seen when light passes through a small slit, and the rainbow effect in CDs.
What is the distance between fringes for 633 nm light with given parameters?
Calculate using the formula provided.
What is the absolute refractive index of water?
4/3.
What formula is used to find the spacing between the two slits in a double slit experiment?
d = (mλ) / sin(θ), where m is the order of the fringe.
What is the distance between the two slits in Young's double slit experiment?
0.15 mm.
What are the conditions necessary for the formation of constructive interference?
Waves must be in phase and have a path difference that is an integer multiple of the wavelength.
What is the speed of light in vacuum?
3 × 10^8 m/s.
What is the distance light travels in glass for the given problem?
10 cm.
How do you calculate the speed of light in water?
Speed of light in water = Speed of light in vacuum / Absolute refractive index of water.
Calculate the fringe width when the slits are 1.0 mm apart and the distance to the screen is 1.0 m using light of wavelength 500 nm.
Fringe width (β) = (500 x 10^-9 m * 1.0 m) / (1.0 x 10^-3 m) = 0.5 mm.
How will a diffraction pattern change when white light is used instead of monochromatic light?
The diffraction pattern will show a spectrum of colors instead of a single color due to the different wavelengths in white light.
What is the separation between the slits in the double slit experiment?
0.2 mm.
Differentiate between interference and diffraction.
Interference is the superposition of two or more waves, while diffraction is the bending of waves around obstacles or openings.
What is a key feature of the intensity distribution in diffraction?
It typically shows a central maximum that is much brighter and wider than the subsequent maxima.
What is the path difference for the third dark fringe in Young's experiment?
The path difference is 3λ + λ/2 (3 times the wavelength plus half a wavelength).
Why are diffraction gratings preferred over prisms in spectrographs?
They are more efficient and do not absorb light.
Given laser light of wavelength 640 nm produces bright fringes separated by 7.2 mm, how do you calculate the wavelength of another source producing fringes separated by 8.1 mm?
Use the ratio of fringe separations to wavelengths: (640 nm / 7.2 mm) = (λ / 8.1 mm).
What is the refractive index of glass?
1.5.
What are the possible answers for the speed of light in glass?
a) 7.95 × 10^8 m/s, b) 9.95 × 10^8 m/s, c) 1.95 × 10^8 m/s, d) 3.95 × 10^8 m/s.
What does the superposition principle state?
When two or more waves superimpose, the resultant displacement is the vector sum of the individual displacements.
What happens to the fringe width in Young’s double slit experiment when immersed in a medium with a refractive index of 1.5?
The fringe width becomes one third of the ordinary fringe width.
Using the given data, what is the calculated spacing between the two slits?
3.43 × 10^-4 m.
How does Huygens Principle relate to the bending of waves at the interface of two media?
It explains how wavefronts change direction due to different speeds in different media.
What happens to the fringe width if the whole setup is dipped in water?
The fringe width decreases.
What is phase difference?
The difference in the phase angle of the two waves.
What is the primary characteristic of the intensity pattern in interference?
Interference produces a series of bright and dark fringes due to constructive and destructive interference.
How does the intensity pattern of diffraction differ from that of interference?
Diffraction results in a more spread out intensity pattern with gradual changes, rather than distinct bright and dark fringes.
What is the time taken by light to travel 10 cm in glass?
500 × 10^-10 s.
What is the distance from the slits to the screen in the double slit experiment?
1 m.
What is the effect of performing the double slit experiment in water on fringe width?
Fringe width decreases due to the higher refractive index.
How far from the central line was the second bright band observed?
70 mm.
What is the time taken by waves to move from one wavefront to another in a medium?
The same for all wavefronts.
What do the dotted lines in the wave diagram represent?
Troughs of the waves.
What happens to water waves when they pass through a narrow opening?
They spread out and create a pattern of waves on the other side.
What is the formula for fringe width in a double-slit experiment?
β = λL / d, where β is the fringe width, λ is the wavelength, L is the distance to the screen, and d is the slit separation.
What is the function of the slit in a spectrograph?
It allows a small portion of incident light for spectral analysis and filters out stray light.
What is the formula for calculating fringe width in Young's double slit experiment?
Fringe width (β) = λD / d, where λ is the wavelength, D is the distance to the screen, and d is the separation between the slits.
Why is diffraction of light often a faint effect?
Because the wavelengths of visible light are very small compared to the dimensions of ordinary objects.
What defines coherence in waves?
The condition when two waves travel with the same phase or constant phase difference and the same frequency.
How does the angular separation of interference fringes change in Young’s experiment if the distance between the slits is increased?
The angular separation decreases.
What do diffraction gratings consist of?
Thousands of narrow, closely spaced parallel slits.
What are the bright spots formed in a double slit experiment called?
Fringes.
In the context of Huygens Principle, what does each point on a wavefront represent?
A source of secondary wavelets.
What is the formula to calculate the slit separation in a double-slit experiment?
d = (n * λ * L) / y, where n is the order of the fringe, λ is the wavelength, L is the distance to the screen, and y is the distance from the central line.
What is the path difference between lines AP and BP if given as 3λ - 1/2λ?
2.5λ.
What does the variable 'x' represent in the double slit experiment setup?
The distance from the double slit to the screen.
How does the fringe width change when the double-slit experiment is immersed in water with a refractive index of 1.5?
The fringe width decreases because the effective wavelength in water is λ/n.
What does the variable 'y' represent in the double slit experiment?
The distance from the center of the screen to the fringe.
In Young's double slit experiment, would the same pattern emerge if two separate sources of light were used?
No, because the two sources would likely not be coherent, leading to an inconsistent interference pattern.
What is the frequency of light used in the double slit experiment performed in air?
6 × 10^14 Hz.
What is the purpose of the detector in a modern slit spectrometer?
It captures the spectrum and feeds it into a computer for further analysis.
What is interference of light?
The redistribution of light energy due to the superposition of light waves from two coherent sources.
What principle can be used to derive the law involved in diffraction?
Huygen's Principle.
What is the refractive index of the liquid if the speed of light in air is 3 × 10^8 m/s?
1.25.
What does 'μ' represent in the context of light?
The refractive index of a medium.
What is the wavelength of the monochromatic light used in the experiment?
450 nm.
What type of interference is produced at point P if the path difference is 2.5λ?
Destructive interference.
What is the relationship between the distances of the 4th maxima for blue and green light?
X_blue < X_green.
What type of pattern is observed when a second identical slit is placed beside the first?
An interference pattern.
What instrument do scientists use to study the spectra of stars and galaxies?
A spectrograph.
What would be the fringe width if the separation between the slits is halved and the distance of the screen from the slits is doubled?
Fringe width would be 1.0 mm.
What causes the bright and dark fringes in interference patterns?
The superposition of waves from coherent sources leading to constructive and destructive interference.
What type of wavefront will emerge from a distant light source?
Plane wavefront.
How do you calculate the fringe width in a double slit experiment?
Fringe width = (wavelength × distance to screen) / slit separation.
How far are the double slits from the screen?
3.00 m.
What is constructive interference?
The phenomenon where crests or troughs from two waves meet, creating a bright spot.
What does the equation sin(i) sin(r) = 1 imply?
It shows the relationship between the angles of incidence and reflection.
How does the wavelength of water waves affect diffraction?
Longer wavelengths diffract more than shorter wavelengths.
Which color band is wider in the diffraction pattern?
The band with higher wavelength (red) is wider than the band with smaller wavelength (violet).
What is a common observation of diffraction in water waves?
The formation of circular wave patterns after passing through an opening.
What factors influence the extent of diffraction in water waves?
The size of the opening or obstacle relative to the wavelength of the waves.
What is the width of the fringe patterns in the interference experiment?
To be calculated based on given parameters.
How does the fringe width change when the distance of separation between the slits and screen is doubled?
The fringe width doubles.
How do you calculate the speed of light in vacuum using the speed of light in glass?
Speed of light in vacuum = Speed of light in glass × Absolute refractive index of glass.
What is the refractive index of glass?
1.5.
What is the relationship between the velocities of light in two different media?
The ratio of the velocities is equal to the inverse ratio of their refractive indices.
Give an example of coherent sources of light.
Lasers.
What is the wavelength of light used in the second double slit experiment?
600 nm.
How do you calculate the time taken by light to travel a distance in glass?
Time = Distance / Speed of light in glass.
What is the speed of light in water?
2.25 × 10^8 m/s.
What type of wavefront will emerge from a point source?
Spherical wavefront.
What is the phase difference for the third dark fringe in Young's experiment?
The phase difference is 9π radians.
What is the distance between fringes produced by light that is 7.50 mm apart on a screen 2.00 m from double slits separated by 0.120 mm?
Use the formula to find the wavelength.
What is the speed of light in water?
2.25 × 10^8 m/s.
What is the appearance of the diffraction pattern when using white light?
The central maximum is white and the other bands are colored.
What is the difference between coherent sources and monochromatic sources of light?
Coherent sources maintain a constant phase relationship, while monochromatic sources emit light of a single wavelength but may not be coherent.
What does the collimating mirror do in a slit spectrometer?
It focuses the light onto the diffraction grating.
What is the significance of the formulas learned while proving?
They help understand the behavior of light as it passes through different media.
What is path difference?
The difference in the path traversed by the two waves.
What is the angular width of the fringe formed in the second experiment?
0.1 °.
What are the two methods to disperse light in a spectrograph?
Using a prism or a diffraction grating.
What causes the interference of light?
The superposition of light waves from two coherent sources.
In which phenomenon do you observe a more complex intensity pattern, interference or diffraction?
Diffraction, as it involves the bending of waves around obstacles and openings.
Why are coherent sources necessary to produce a sustained interference pattern?
Because they maintain a constant phase relationship.
Why is every incident photon considered precious in spectral analysis?
Because they are crucial for obtaining a spectrum from faint sources.
What is the separation between the double slits?
0.0800 mm.
How does a prism affect the dispersion of light compared to a diffraction grating?
A prism disperses blue light more than red light.
State one feature that distinguishes an interference pattern from a diffraction pattern.
Interference patterns have evenly spaced fringes, while diffraction patterns show varying intensity and spacing.
What is the speed of light in glass?
Calculate using the refractive index and speed of light in vacuum.
What are the wavelengths of light used to observe the interference patterns in the given setup?
480 nm and 600 nm.
What is a significant advantage of using diffraction gratings regarding light response?
The response is linear across the spectrum.
