Identical waves that begin propagation at the illfk w7:n at kd25:;;xn;jnesame time leave from two different sources and arrive at the saj;tlend: 7:w2xfk;in 5 na k;lme 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 $X$ ?

  When does diffraction ocpmne4blgpc-*)mq h.+2 w d3gocur?

  Which property of a wave does not change aeh*eco( 1rc med+yllm8w7w gc2wb810s a result of refraction?

  A ray of light is incident on a matejdx -u+ dv,o, h8pgf,prial made from three layers, each having a different optical density, udhp 8 x+dgpjo,fv,-,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?

  A student is investigating the interference of waves. They set up c73wg+ sx ndl2cyu 8v/qoherent waves produced at points +v278wlungqc 3yd/ xs$\mathrm{S}$ 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?

  Which of the following images shown below best represents the pysby4;+xq d+ qxp j:x/ath of visible light traveling through a glassyby/dj+ +4;xq xqpx:s prism?

  The diagram shows two waves. Onqjnbo(0s4 ias9 90bjr e 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 phrase correctly completes the following di-l 8(ei,y8 l8dhlspsentence?

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

  A monochromatic laser beam is shone into the surface of a tank filled with ,t 6xf wy5i:tubv7yg :water. The effects on the laser beam due to the water are obsew:yt6vgxf5 :u,b7 t yirved.

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

  When moving from material).b ag*8f fxeg $A$ 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?

  Which row correctly describes the conditions for constructivz.,/8gx uu lyce and destructive interference in a double-slit diffraction patte /c8ulygzux ,.rn?

  When a light ray enters a denser medium and 7m10x:r y4wl ih)+kybixf( ujrefracts, some of the characteristics of the wave will change. Which of the following options is correct about this c1 jhmx ifyr: k0(y lxw)+biu74hange?

  Young's double-slit experiment is setup as shd5h)6br qq5jk own, including a monochromatic source, a single slit, a double slit and a screen. What qd5hq ) b65jrkis the purpose of the single slit in this experiment?

  The diagram below shows an arrangement used to investigate double slit interfesij hayw5cp, t8r gj8+((g sd:rence using microwad8h+p,i as yjj cr(g(ws:8gt5ves.



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.

  In a Young's double-slit experiment, the spacing of the double slits is 1:x0a d7m.gq osit/or$d$ 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 $s$ ?

  This diagram below shows two apertures throuoz; ozl, m22vugh which planar waves are passed as they are moving to the lezzu2, lo2v mo;ft. The wavefronts show crests moving in phase. Given this information, at which 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?

  Diamonds are highly valued because of their sparkz1/ddsb+ zyk1crve3isy z( mbjf ,irp 0,h07(le. 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. Howeverc(s(1djrhzzb mkd0 ,3s/vb7, ypf0yzi e i1+r , 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?

  Two waves from individual point uqlnljx2un*(w v 6+bg nq h5je4*cp,:sources meet at a point $X$. Which of the following conditions is necessary for stable interference pattern to be observed at point $X$ ?

  The effect of a double slit on monochromatic light is observed a;bdes .ki5m,jh tj(1qx8n um9i5rk 1by the set up in the diagram belowejrnd(;,ujkx 5 11hq9m8 i.bkmait5s .



Interference fringes are seen on the screen.

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

  $\mathrm{K}$ 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?

  A double slit interference experiment is conductef jcd/g1-gt v+u-x to7d using monochromatic light of tox7t vf/ud-jg cg+ 1-wavelength $\lambda$. 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?

  Which image shows the correct ray diagram acg7jc3 q9zae k5x l,)z*b 4wbfor light passing from air into water?,3alw4)b9z* eazgcb xj5k7c q

  Our fingerprints are made up of a series of ridges on sjs0 zgg+o4v0vt: mh1the end of the finger. These ridges can be 'read' by electro0v j o1zsgtsgv:+0m h4nic 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?

  Ray diagrams can be used to show the reflectionb 9w,mzu.bc9 k, refraction and transmission of b.9zbw9, cm uklight at the boundary between media.


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

  Which of the following optir,+w 7pgyzc9j ons will alter the frequency of a wave?

  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?

  The diagram shows a wave approk cf7l5;4gqzg n0 6kstaching an aperture.


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

  The double-slit equation descao8n75eigb()5 w u aleribes the relationship between the separation distance of the fringes on the screen, sl igwb75e(eao8)a n5u , the distance between the screen and the slits, $D$, 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?