A beam of parallel light with a wavelength of w8o. qh4g xnw*) cnc2qo bqy48$λ$ is incident on a narrow slit. A diffraction pattern is formed on a distant screen. The angle of diffraction between the central maximum and the first minimum is $θ$. What would be the angle of the first diffraction minimum for the light with a wavelength of $3λ$?

  A radio with a bright light is placed outside the doorway of long, dark room as shown. A student in a corner near the door can hear the sound of the radio while standing in the dark region of the room.

  

  Wavefronts travel across a boundary between two media as shown.


Which of the following correctly describes the change, if any, in the speed, wavelength and frequency of the waves as they pass from across the boundary?

  A light ray is incident on a semicircular glass block from the air. The glass has a greater refractive index than air. Which diagram correctly represents a possible path of the light ray as it enters and leaves the block?

  In a single slit diftzij4q xi4 d0h)4j9f wfraction experiment, incident light passes through an aperture and a diffraction patterni9 jfizt440w 4hqd )jx is observed on a distant screen. $X$ is a point on the screen between the second-order minimum and the first-order minimum. $Y$ is a point at the centre of the principal maximum.


Which one of the following could be the ratio of the intensity of light on $X$ to the intensity of light on $Y$?

  Light of wavelength n 4d/qs::l iqm$λ_1$​ and $λ_2$​​ is incident on a diffraction grating with the slit spacing of $d$. A series of bright lines are formed on a screen.


What is the ratio $\frac{sinθ_1}{sinθ_2}$ ?

  Monochromatic light falls on a diffraction grating and a diffraction pattern is formed on a screen. A wider beam of light is used so that more slits of the same diffraction grating produce the interference pattern. Which one of the following is correct in terms of intensity and width of primary maxima?

  A laser beam passes through a narrow slit and incident on a screen. A di)a g vlr 8zv xgk(m9uelpl2379ffraction pattern is observed on the screen. The variat u 2xv7eglrp)l93(8a z lkv9mgion of intensity $I$ of light on the screen with distance $x$ is seen in the graph below.


Which of the following graphs best represents intensity distribution with distance when the slit is replaced by one of greater width? The original distribution is shown with a dashed line.

  A student investigates the refraction of light. A light beam emitted from the ray box is incident on a transparent block. The ray trace sheet and the position of the ray box and the transparent block are shown below.


The distances a and b are measured. Then the measurement is repeated for different values for angle $θ$. The variation of b with a is plotted on the graph below according to obtained data.

Draw the line of best fit for the plotted data on the graph.
2.Theory suggests that
$n=\frac{a}{b}$
Where $n$ is the refractive index of the material and has a constant value.
(1)Suggest whether the data is consistent with the theoretical prediction.
(2)By using the graph calculate n with its absolute uncertainty for the data point when a is measured to be 3.0cm. n =   
(3)The accepted value for the refractive index of the transparent block is 1.71. Comment on your result.
3.Suggest why using the line of best fit to find the value for $n$ is better than finding $n$ from an individual data point.

  A parallel beam of light with a waveli(; jo00kg /fjdt/ibus+k9 ycength of $500\,nm$ passes through a narrow slit with a slit width of $2\,μm$. The angle of diffraction for the first minimum is θ. What is the new angle of diffraction for the first minimum when the slit width is changed to $4\,μm$ and the wavelength of the light is now $250\,nm$?

  The diagram shows a beam of light passing from medium $X$ to medium $Y$.


If the angle of incidence of the light increases, which of the following changes can be implemented to keep the angle of refraction the same?
I. Medium X can be replaced with another medium which has a lower refractive index.
II. Medium X can be replaced with another medium which has a higher refractive index.
III. Medium Y can be replaced with another medium which has a higher refractive index.

  Three monochromatic wpydv ch38/ra1-a f)xlight sources, $K$, $L$, and $N$, are incident on a single slit separately. The diagram shows obtained diffraction patterns on the screens for each light source along with the relative widths of their central maxima.

In which option are the possible colors of the light sources given correctly?

  1.Young's double slit experiment is used to determine the wavelength of a monochromatic light source.

The separation between the two slits $d = 0.15 ± 0.01\,mm$.
The distance between the double slit and the screen $D= 1.30 ± 0.05\,mm$.
The distance between the bright fringes $s= 3.2 ± 0.1\,mm$.
(1)Explain why a double slit is used instead of two light sources.


(2)Determine the wavelength of the light, including its uncertainty.1 significant figure。 λ =    nm

2 significant figure λ =    nm
(3)The experiment is repeated with a larger distance D but the same measurement tools were used.
State and explain the impact of this change on the uncertainty on the calculated value for wavelength.
2.(1)The experiment was repeated by changing the separation between the slits and the screen.
The graph shows the variation of the distance between the bright fringes $s$ and the distance between the double slit and the screen $D$.

Describe without calculations how the wavelength can be determined using the graph.
(2)State the effect of increasing the number of slits on the intensity of the fringes and on the experimental result for the wavelength.

  A student carried out an experiment using a laser beam incident on double slits with negligible widths. An interference pattern is observed on a distant screen.


Which of the following is correct for the pattern observed on the screen when the slits of non-negligible widths are used with the same slit separation?
I. It is modulated with the single slit diffraction effect
II. Central maximum is brighter
III. Fringe spacing is larger

  A parallel beam of light passes through two parallel slits and an interference pattern is formed on a distant screen. The fringe separation is too small to measure. Which of the following would increase the fringe separation?

I. Increase the distance between slits and screen
II. Replace the light source with one with a longer wavelength
III. Increase the slit separation

  Sound waves in water travel approximately 4.5 times faster than in air. Which of the following diagrams correctly shows the wavefronts of sound as they pass from air to water?

  A monochromatic beam of light is incident on a double s7 ,o2c0k6njoaee.g wk rggv (:lit arrangement where the slit caj0og,e7kw.g( gnk6vroe:2 separation is $9.0\times10^{−5}\,m$ and the slit-screen distance is 1.0m. The graph below shows the relative intensity of the light reaching the screen with respect to the distance from the central point of the pattern.


What is the wavelength of the light?

  The diagram shows a light ray that travels from air into a glass block.


(1)State what is meant by the refractive index of a medium.
(2)Knowing that
The refractive index of glass = 1.5
The angle of incidence = $40^{\circ}C$
Draw on the diagram a ray to represent the path of light in the glass block.​
(3)Calculate the angle of refraction inside the glass block.​$θ_2$=   $^{\circ}C$
2.Another light ray travels inside the glass block as shown in the diagram.$θ_c$=   $^{\circ}C$

Determine the minimum angle $θ$ for which this reflection would occur.

A parallel beam of red light passes through two parallel slits with negligible width and an interference pattern is formed on a distant screen.


$θ$ is the angle that shows the diffraction angle of the light waves reaching any point on the screen.
1.Explain why an interference pattern is observed on the screen.
2.On the axes below, sketch a graph to show how the intensity I of light on the screen varies with angle $θ$.
(There is no need to add values to the axes)

3.In the arrangement, the red light source is replaced with a blue light source with the same intensity. How would the drawn graph in (a) (ii) differ?

  Two speakers emit identical sound waves. A sound sensor moves along the line $XY$. As the sound sensor moves it detects locations where there is almost no sound. Some distances between the speakers and points $A$ and $B$ are given on the diagram.


1.Explain why there are quiet locations.
2.The speed of sound is $340\,ms^{−1}$. Point $O$ is where the highest intensity is received by the sound sensor. Point $A$ is the first quiet spot as the sensor moves from $O$ to $X$ and point $B$ is the second quiet spot as the sensor moves from $O$ to $Y$.
(1)Show that the frequency of the sound is approximately $140\,Hz$. f ≈    Hz
(2)Calculate the distance $∣S_1​−B∣$, distance between Speaker 2 and point $B$. $∣S_1​−B∣$ =    m

  In Young’s double-slit experiment, monochromatic light is incident on two slits and a diffraction pattern is observed on a distant screen. The graph shows the variation of intensity with distance from the centre of the pattern.


The slits are replaced by two slits with negligible width. What is the effect of this change on the interference pattern?

  A beam of monochromatic light is incident on a single slit. After passing the slit, a diffraction pattern is observed on a screen of distance D to the slit.


Which of the following is correct for the diffraction pattern observed on the screen when the D is doubled?

  Incident light of wavelength 600 nm is emitted towards two slit6:w( xp ,agvr/f n7+jbjc bws4s separated by 1 μm. The interference pattew6:,bv b4gnjjx+fr(p acsw7 /rn is observed on a wall. The distance between two adjacent maxima is 1.2 m. What is the distance of the wall from the slits?

  A wave is incident onmqd(sl -o7 b)n a boundary between two media, $X$ and $Y$. The wave travels faster in medium $Y$ than in medium $X$
Which of the following diagrams shows a possible path for this wave?

  A speaker emits sound waves toward a boundary between dry, cool air and moist, hot air. The speed of sound in the dry air is $340\,ms^{−1}$ and speed of sound in the moist air is $375\,ms^{−1}$. Three wavefronts enter the boundary with an angle of $51^{\circ}C$ as shown.


1.Draw lines to show wavefronts in the moist air.
2.For the sound traveling in the moist air, calculate the angle between the wavefronts and the boundary. θ =    $^{\circ}C$
3.Now the moist air region has been replaced with another medium $X$. Determine the minimum speed of sound in the medium $X$ so sound cannot enter. v =    $ms^{-1}$

  A monochromatic light beam of wavelength λ is diffraj7pb i3pa r 5;m(ib:ructed at a single slit of width; ri(7bj: umrbi3ppa 5 $b$. After passing the slit, a diffraction pattern is observed on a screen a large distance away. The width of the central maximum is $w$.


The screen is moved closer to the slit. Which of the following changes, done separately, could result in no change in $w$?

  A microphone is emittha/fnr. 7g-ruc )t; foing a sound wave with a wavelength of $15\,m$. Tom is $5\,m$ further away from the microphone than Mary. What is the phase difference of the sound wave, in radians, between them?

  Light with a wavelength of $750\,nm$ is incident on a single slit. The slit width $b$ is comparable to the wavelength of the incident light.


1.State what is meant by diffraction.
2.(1)On the diagram; sketch the wavefronts after passing through the slit.
(2)Describe the pattern observed on the screen.
(3)The slit width is slowly increased until it is much wider than the wavelength. Explain the effect on the observed pattern.
3.The single slit is now replaced with a pair of slits of spacing $d$ as shown.

(1)Describe the pattern observed on the screen.
(2)Knowing that
Distance between the slits $d=150\,μm$
Distance between the double slit and the screen $D=2.3\,m$
Calculate the distance between the centers of two bright fringes. s =    m
(3)Explain how the widths of the slits will affect the appearance of the pattern on the screen.

  

  

Two sources $A$ and $B$ produce waves of amplitude $a$, and period $T$ on the surface of a swimming pool as shown. The wave generator $A$ is turned on at time $t=0$, and $B$ at time $t=\frac{T}{2}$​. Both generators create a crest when first turned on. The wavefronts shown in the illustration are one wavelength apart each. Determine the amplitude of the oscillation of the medium at point $C$.

  Light of wavelength x:y/-j k3 ,tya+ upqi ntr7,jt$400\,nm$ and $700\,nm$ is incident on a diffraction grating that has 700 rulings per$mm$. A series of bright lines are formed on a screen. The angles for different maxima for the light are shown.


1.(1)In order to observe bright lines on the screen, the light incident on the diffraction grating must be coherent. What is meant by coherent light?
(2)Find the value for $\frac{sin θ_1}{sin θ_2}$ =   .
2.(1)Determine the maximum number of bright fringes of the same colour that can be observed on the screen.
(2)For the same wavelength of light, what change can be made to the arrangement to increase the number of bright lines observed?

  Two water waves $X$ and $Y$ travel on the same horizontal level as shown in the diagram.


The two waves have the same period of $3\,s$ and different amplitudes.
1.State what is meant by the principle of superposition.
2.At t=0 the two waves are just about to overlap.
(1)Sketch the wave pattern at $t=1.5\,s$.
(2)Sketch the wave pattern when the two waves completely overlap and name the type of interference that is occurring.
3.A wave with amplitude A is observed to have an intensity $0.42Wm^{−2}$ at a distance $0.5\,m$ from the source.
(1)Determine the intensity of the wave at distance $0.5\,m$ when the source amplitude $3\,A$. I =    $Wm^{-2}$
(2)Determine the distance from the source at which the intensity is $0.84\,Wm^{−2}$ when the source amplitude is $3\,A$.

  A light and a heavy spring are attach*ze g467ekq n n48 ok ffxp2;,jtrnk)eed at point $Y$. A pulse was generated in the light spring and incident on the heavy spring. The positions of transmitted and reflected pulses after some time are as shown.


Which of the following is true about the incident pulse?

  A parallel beam of light passes through a narrow slit and a diffraction pattern is observed on a distant screen. A student draws a graph to show the variation of the angle of diffraction $θ$ between the central maximum and the first minimum with wavelength $λ$ of the beam.


What can be deduced from the graph and how would the quantity be deduced?

  Two water waves with the same amplitude are traveling towards each other. The water level against position graph of one water wave is shown below. The equilibrium water level is $5\,cm$.


What are the maximum and minimum water levels when the two waves overlap?

  A beam of light is incident on a diffraction grating that has $N$ lines per $cm$. An interference pattern is observed on a distant screen. The graph shows the variation of deflection angle $θ$ for the fifth maximum with wavelength $λ$ of the beam.


Which of the following gives the gradient of the graph?

  A single narrow slit of width $b$ is used to diffract the radiation of a microwave transmitter. A receiver is positioned at distance of $D$ from the slit. The receiver is moved from point $A$ to point $C$. At point $B$, the intensity of the radiation is minimum for the first time.

  A coherent light is incident on a double slit that has slit sa0v(ukwn*hr ).xk ( sgo58cxleparation of $d$ and slit width of $b$. An interference pattern on a screen is observed. The graph shows the variation of intensity with distance from the centre of the pattern.


$S_1$​, $S_2$​ and $S_3$​ are the separations between various points on the pattern and the center of the pattern. The distance between the screen and slits is $D$. What is the wavelength of the incident light?

  A beam of monochromatic light is incident on a single slit of width $b$. After passing through the slit, a diffraction pattern is observed on a screen of distance $D$ from the slit.


1.What is meant by monochromatic light?
2.A student wants to measure the width of the central bright fringe of the diffraction pattern observed on the screen.
(1)The width of the central bright fringe is too small to be measured. Suggest three changes in the arrangement to solve this issue when each of them is implemented separately.
（2）The width of the central bright fringe is measured as 2.4 cm after the relevant change in the arrangement is implemented. The distance $D$ between the slit and the screen is 50 cm while the wavelength of used light is 600 nm. Estimate, in $m$, slit width $b$. b =    $\times 10^{-5}m$
3.The student wants to be sure of the calculated value of slit width. They therefore decide to repeat the experiment with different wavelengths.
On the axes below, sketch a graph to show how the angle θ of the first diffraction minimum from the central maximum varies with wavelength.
(There is no need to add values to the axes)

Microwaves generated by a microwave transmitter is diffracted while passing through a slit. A receiver is positioned at a long distance of $D$ from the slit. The receiver is moved between point $A$ and point $C$.


1.Outline what is meant by diffracted microwaves.
2.The receiver records the intensity of the microwave for various positions between $A$ and $C$. It measures zero intensity two times while moving from $A$ to $B$.
(1)On the axes below, draw the variation of measured intensity $I$ with the position $x$ while moving from $A$ to $C$. (There is no need to add values to the axes)

(2)The slit used in the arrangement is replaced by one of greater width. State and explain the changes in the intensity-position graph you have drawn in (b)(i)

  In a two slit interference experiment, light of wavelength 600 nm is sent to slits with a width of $b$. An intensity pattern is observed in a narrow range as shown below.


The distance between the slits is $d$. Calculate the ratio of $\frac{b}{d}$

  Monochromatic light of wavelength λ is diffracted while passing through a narrow slit. The three labeled light rays emerge from the top, halfway and bottom of the slit meet at a first diffraction minimum on a distant screen.

  Light with wavelength λ is incident on a diffraction grating. The maximum number of bright fringes that can be observed on the screen is 9. Which of the following gives the number of slits per cm in the grating?

  Monochromatic light of wavelength λ falls normally on a diffraction grating. The maximum number of maxima that can be observed using this setup is 9. Which of the following can be the slit separation of the diffraction grating?

  The speed of light i)s8xyuc fyzw 8;ttup9(c q7h (n medium $X$ is $\frac{2}{3}$ of the speed in medium $Y$, while the speed of light in medium $Z$ is $\frac{4}{5}$​ of the speed in medium $Y$. When light travels from medium $X$ to medium $Z$ with an angle of incidence $i$, what is the angle of refraction $r$?