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?

  This diagram below shows two apertures uzam-0ar45fm gooi -4ea, xa9 through which planar waves are passed as they are moving to the left. The wavefronts show crests moving in phase. Given this information, at whichr5if 4a-a oax,m oe4-g0mu z9a point will the amplitude 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?

  Young's double-slit experiment k4 j5xbenso5 x1 /h2elis setup as shown, including a monochromatic source, a single slit, a double slit and a screen. What is th5l4bx /2enhkjoxse51 e purpose of the single slit in this experiment?

  The diagram below shows an arrangement used to investigate double sli( *:tva*csk 6z 6 -s1etsuwyust interference using microwaves.v(auku:s1sy z-* cw6estt6*s



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 row correctly describes the conditions for co2;b /2ttoncmo1n4rj( s n ak:anstructive and destructive inteab o:2nka; 1sn(4/2t t cjornmrference in a double-slit diffraction pattern?

  Which of the following images shown below best rec daxa4q;,/ hib4*.ezobl 4td)i7 n2 2npvas zpresents the path of visible light traveling throul,)nhpd4 .sdcnqa72 ab* i a4bi4ze/ x; 2tozvgh a glass prism?

  A ray of light is incidentkyym u ;p9is4sa0*ga 0 on a material made from three layers, each having a different optical density, so yp ;*04umsa9kigya0 s 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?

  Which image shows the correct ray diagram for light passing from air souqsz4qn x 94.aqfk *;j-a)q into water? qj.x oa*-uzk49qsn f;s qaq4)

  When moving from material1 1 p3*i6.madg-hnp ruwfla5f $A$ 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 student is investigating awij(9cj om+ +the interference of waves. They set up coherent waves produced aoa+ij j (mcw+9t 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?

  Ray diagrams can be used p,tj-26 f p v:rexczo2to show the reflection, refraction and transmission of light at the boundary betweex,2zfo-ep6r:tvc 2jp n media.


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

  Which phrase correctly completes the following sesbh.(kmx ogy.60exby lyw5 9)ntence?

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

  The double-slit equation describes the relationq:5rz i; syl,jwo5p5f/ 1f3we,s 3kdzsdh-wyship between the separation distance of the fringes on the screen, s, the distance between the screen and the sfk3 z-p5/esjwyyrs ld53w w;: ,1,iofs5 dzh qlits, $D$, 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?

  Which property of a wave does not change as a result of rgrx2ml tn +fb67+j.-d*nk pg pefraction?

  Identical waves that begin propagation at the same time leave from two differ p*5+r ng44ckq69vgoyabj78 c s4bj bdent sources and arrive at the sam cbk* ra8 pb4 gcqvj9ojdgn6+y54s4b7e point point $X$. 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 $X$ ?

  The diagram shows a wavkjbr +j0;4e)d2bg fakh 91tj+qnat*ue approaching an aperture.


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

  Diamonds are highly valued because of their sparkloskkpu ;2qp/7lxn8) f)ce d+ie. This is caused by total intern7edsf/2ko kcu8) p;ix n)q+l pal 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 diamonds.

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?

  A double slit interference experiment is conducted using monoco ;:ctl2h/,yu rm uz6fhromatic light of wc;uf ,2/rl o y6m:zhtuavelength $\lambda$. 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 refracts, so; qq;alwds;e 2me of the characteristics of the wave will change. Which of the following options is correct about td wlq; ;aes2;qhis change?

  Two waves from individual point sowta-*+jzzij9o:e 4 f curces meet at a point $X$. Which of the following conditions is necessary for stable interference pattern to be observed at point $X$ ?

  When does diffraction occur+fio ob 42t)*qgld) gi?

  The diagram shows two waves. One wave is emitted from sjpx./tg:) amy w79czyob9c 5u n,3zvmource $s_{1}$ 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?

  The effect of a double slit on monochrosru*6fwzvx)gc nfh(f 2-( * oomatic light is observed by the set up in ts fco 6rh* w( xu*n2-f)gv(zfohe diagram below.



Interference fringes are seen on the screen.

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

  Our fingerprints are made up of a series ox4v kaprd4y pq--2x ;wf ridges on the end of the finger. These ridges can bx d2;-x4a 4kvyprp-qwe 'read' by electronic devices.

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?

  In a Young's double-slit experiment, the spacing)q gi04vy+k8cujn7m c of the double slits 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 $s$ ?

  A monochromatic laser beam is shone into the surface of a tank filled with9wu;; g)jcmrf h hgl:7 water. The effects on the laser beam due to ; l:j cur7)9 gfw;hhgmthe water are observed.

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

  Which of the following options will alter the frequency of a svst(u t28rn9wave?

  $\mathrm{K}$ 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?