A sound source $X_{1}$ is positioned $w \; cm$ to the left of sound source $X_{2}$. Both sound sources are $y \; m$ below the detection line $A B$. $A B$ runs parallel to $X_{1} X_{2}$. When a sound detector is slowly moved along the line $A B$, a maxima is first detected at $P$, followed by a minima at $Q$, with another maxima at $R$ and a minima at $S$. $P Q R S$ are all equidistant apart with $X_{1} S=X_{2} S$.

Which one of the following is a correct expression for the wavelength of the sound?

  When moving from material s,-02qt ( fkjelwjc4 p$A$ to material $B$, the direction of a ray of light moves away from the normal. If $n_{A}$ and $n_{B}$ are the refractive indices of materials $A$ and $B$ respectively, then which of the following statements is true in this situation?

  A monochromatic laser beam is shone inaou u8sd0x8s-+y vhp 71gtw9yax*7ssto the surface of a tank filled with water.*dx8uoy+us 1wg797-8apss ytxahsv0 The effects on the laser beam due to the water are observed.

How will the properties of the light be affected by the water?

  Ray diagrams can be used to show the reflection, refraction and transmission (p44xucjb 4 jjof light at the bojp44j b(4jxu cundary between media.


In the diagram, what feature does $X$ represent?

  The diagram shows two waves. Onejl*x a2x6g*n2l3zac s wave is emitted from source $s_{1}$ and travels to point $P$. The other wave is emitted from source $s_{2}$ and travels to point $P$.



What is the path difference between the waves?

  Which property of a wave does not change apgcqt + 54;ccjs a result of refraction?

  The double-slit equation describes the relationship betweenfut6+ ,lgzb5r3pb).ig9pzq d the separation distance of the fringes on the screen, s, the distance between the screen and the slitzdlq bp z,)urpt+ g 953.6gibfs, $D$, the separation of the slits, $d$, and the wavelength, $\lambda$, of the light.

$$
s=\frac{\lambda D}{d}
$$

Which line gives the correct units for the quantities?

  A student is investigating the interference ofajy) 4.p gyfh: waves. They set up coherent waves prh4)yajy:. pgfoduced at points $\mathrm{S}$ and $\mathrm{T}$ and travel outwards in all directions.

The line $X Y$ is halfway between $S$ and $T$ and perpendicular to the joining line $S$ and $T$. The distance $X Y$ is much greater than the distanceST.



Which line or lines would an interference pattern be seen along?

  A double slit interference experiment is conducted usingxi; fhj./5qb e nh;/(8qxo;z liya nl2 monochromatic light of wavelengte5/ x;;hi (bx 2z lfaoyj/;.ihqln8qnh $\lambda$. The centre of the observed pattern is a bright fringe.



What is the path difference between two waves which interfere to give the second dark fringe from the centre?

  When a light ray enters a denser medium and refrai a+*ny 6wrk(w. fm6ikcts, some of the characteristics of the wave wilwk.6+f6n a*w ky(mii rl change. Which of the following options is correct about this change?

  Diamonds are highly valued because of*xb16n -y6mjmvw4swg their sparkle. This is caused by total internal reflection, which reflects most of the light that falls onto a cut diamond out of the face we see. Fake gems, called 'paste', are often used in jewellery because they are cheaper. However, paste gems sparkle much less than real diamo nm-xv6yj6smwb*gw 14 nds.

The diagrams show a possible path of light through a real diamond, and another through a fake.



If:

- $n=$ refractive index;

- $n_{d}$ is the refractive index of the diamond

- $n_{f}$ is the refractive index of the fake

- $v=$ speed of light

- $v_{d}$ is the speed of light in the diamond

- $v_{f}$ is the speed of light in the fake

Which row in the table contains only statements which must be true?

  Our fingerprints are may k,n w;h -an)m qsg-5g;byc.xde up of a series of ridges on the end of the finger. These ridges can be 'read' by electronic devices.m)ybs wh ;xaq,--gcn.g5;y nk

The diagram below shows a certain type of fingerprint detector below, which works by scattering light when pressure is applied to a plastic screen. The ridges of the fingerprint press the plastic film against the glass when the finger is pressed to the screen.




When not in use, the plastic screen and the glass have a small air space between them. The diagram below shows the two possible paths for the light when the finger is pressed down.




Which row in the table correctly describes the properties of the fingerprint detector that cause the bright and dark patches on the image produced by the camera?

  Which of the following images shown belopadl730 l.sg3rf u jxgoz;r50 w best represents the path of visible light traveling thga;lrl7s5.uz3 xrpf0 o d3j0grough a glass prism?

  Two waves from individual point sources mee,g(8vassb*dlmq *rv (lf +:iyt at a point $X$. Which of the following conditions is necessary for stable interference pattern to be observed at point $X$ ?

  Which phrase correctly completes the following sentencrjdlu0 azg3 qosm.4 ,ts5)1 ece?

In a ray diagram showing reflection, the angle of incidence is the angle between

  The diagram shows a wave approaching an aper5vgcov6it5svf )m3 t5 alt+3 cture.


Which diagram correctly shows the resulting diffraction pattern for the wave?

  $\mathrm{K}$ is the source of a wave of frequency $25 \mathrm{~Hz}$.



The wave travels to point $M$ by two routes, $K \rightarrow L \rightarrow M$ and $K \rightarrow M$. The speed of the wave is $15 \mathrm{~m} \mathrm{~s}^{-1}$.

What is the path difference between the two waves at M in terms of the wavelength $\lambda$ of the waves?

  The diagram below shows an arrangement used to 4. o(hp2gxsjcinvestigate double slit interference using microwaves.xspj2 (oc4 gh.



The diagram below shows the view from above:



The microwaves from the transmitter are polarised. These waves are detected by the aerial in the microwave detector (probe). The aerial is a vertical metal rod.

The detector is moved along the dotted line UY. As it is moved, maximum and minimum signals are detected. Maximum signals are first detected at points $\mathrm{V}$ and $W$. The next maximum signal is detected at the position $X$.

The distances between each of the two slits, $S_{1}$ and $S_{2}$ and the microwave receiver when the aerial is in position $\mathrm{X}$ are $\mathrm{S}_{1} \mathrm{X}=$ $0.3335 \mathrm{~m}$ and $\mathrm{S}_{2} \mathrm{X}=0.3615 \mathrm{~m}$

Find the wavelength of the microwave and select the two correct reasons that explain why the signal strength falls to a minimum between $U$ and $V$, and between $V$ and W.

  Which image shows the correct ray diagram for9 3l9 246x86xw4igp3 rt yrvtzvapz ed light passing from air into water? 463da r69ri wv2 eyp83zxxz 4tgtpvl9

  Which row correctly derkn7yr l0:d o6 ppb-o0scribes the conditions for constructive and destructive interference in a double-slit diffraction patt o7np6:0r0-p kbyor dlern?

  The effect of a double slit on xnh(*8 5uubvp(l g eodh6yo96monochromatic light is observed by the set up in the diagu6gd9pxy6hl8ebu((o vo5h* nram below.



Interference fringes are seen on the screen.

Which of the following changes would increase the distance between the adjacent fringes?

  In a Young's double-slit experiment, the spacing of the double sl p (zugduc0;7v9i1 3cincjh;jits is $d$ and the distance between the slits and the screen on which fringes are formed is $D$. When monochromatic light of wavelength $\lambda$ is incident on the slits the distance between adjacent fringes on the screen is $s$.

Which row shows another arrangement that produces a fringe spacing of $s$ ?

  Identical waves that begin propagation ax aga4 gt42nzm j9:2ktt the same time leave from two different sources and arrive at the same point point x4n 4at2tk9mj ag zg2:$X$. The first source is $18 \mathrm{~m}$ from point $X$. The second source is $10.5 \mathrm{~m}$ from point $X$. The waves of both sources have a wavelength of $3 \mathrm{~m}$. What is observed at $X$ ?

  Which of the following optiomt5i k8h9vml9ns will alter the frequency of a wave?

  Young's double-slit experiment is setup as shown, including a monochx itue z q00c ,.zssstt36l ka(/k1mt;romatic source, a single slit, a double slit and a screen. What zx1ckm z6 t0s kt(el a ;3sitq/0.,stuis the purpose of the single slit in this experiment?

  A ray of light is incident on a material made from three layersn;kwhf )0wpz7:0 prenstl b8: , each having a different optich8kt: 7np0ns0)wzpb re: ;wl fal density, so that in each layer the light travels at a different speed.

- For layer 1: refractive index $=n_{1}$ and the speed of light $=c_{1}$

- For layer 2: refractive index $=n_{2}$ and the speed of light $=c_{2}$

- For layer 3: refractive index $=n_{3}$ and the speed of light $=c_{3}$

- Angle of incidence $=i$

- Angle of refraction $=r$

This is illustrated in the diagram below:




Which is the correct expression for $c_{3}$, the speed of light in the thirdlayer?

  This diagram below shows two apertures through which y8awj, e+ ki7aplanar waves are passed as they are moving to the left. The wavefronts show crests moving in phase. Given this information, at which point will the ae+aky8 7, jiawmplitude of the waves be a minimum?



A flat plate made of glass has a refractive index of $n=1.52$. What is the speed of light within this material?

  When does diffraction occusbzxy3ss 1-2sr?