Data needed to answer questions can be found in the Data, formulae and relationships sheet. Data needed to answer questions can be found in the Data, formulae and relationships sheet.
1
1 The The diagram diagram shows shows water waves water waves passing passing through through a a gap.gap.
What
What property property of of waves waves is is being being demonstrated? demonstrated? [1][1]
A A diffractiondiffraction B B interferenceinterference C C superpositionsuperposition D D polarisation polarisation 2
2 The The diagram diagram show two show two loudspeakers loudspeakers connected connected to the to the same signal same signal generator.generator.
A girl walks from position
A girl walks from position AA to position to position BB..
Which
Which statement statement describes describes what what she she will will hear hear and and gives gives the the correct correct reason? reason? [1][1]
A
A A rise and fall in the loudness as the waves go in and out of phase.A rise and fall in the loudness as the waves go in and out of phase. B
B A rise and fall in the pitch as the waves go in and out of phase.A rise and fall in the pitch as the waves go in and out of phase. C
C A steady loud sound because the waves are in phase.A steady loud sound because the waves are in phase. D
3
3 The graph shows two waves.The graph shows two waves.
Which
Which statement statement is is correct? correct? [1][1]
A
A The waves are coherent and in phase.The waves are coherent and in phase. B
B The waves are coherent but out of phase.The waves are coherent but out of phase. C
C The waves are incoherent and out phase.The waves are incoherent and out phase. D
D The waves are incoherent but in phase.The waves are incoherent but in phase. 4
4 A student sets up a experiment to show interference of light.A student sets up a experiment to show interference of light. He uses two small red LEDs as theHe uses two small red LEDs as the
light sources. light sources. Which
Which of of the the following following explains explains why why he he will will not not be be able able to to show show interference? interference? [1][1]
A
A The light from anThe light from an LED does not does not have a single wavelength.LED does not does not have a single wavelength. B
B The light from an LED does not have a constant frequency and so will not be in phase.The light from an LED does not have a constant frequency and so will not be in phase. C
C The light from the two LEDs will not be in phase.The light from the two LEDs will not be in phase. D
D The light from the two LEDs will not be coherent.The light from the two LEDs will not be coherent. Displacement
Displacement
Time Time
5
5 An experiment is set up to demonstrate interference from different types of electAn experiment is set up to demonstrate interference from different types of elect romagneticromagnetic
radiation. The apparatus is shown below and the dimensions are kept constant for all types of radiation. The apparatus is shown below and the dimensions are kept constant for all types of radiation.
radiation.
Which
Which type type of of radiation radiation will will produce produce fringes fringes which which are are the the closest closest together? together? [1][1]
A
A blue light blue light B
B infrared radiationinfrared radiation C
C red lightred light D
D ultraviolet radiationultraviolet radiation 6
6 aa Describe Describe what what is is meant meant by by thethe diffractiondiffractionof of a a wave. wave. [1][1] b
b Electromagnetic Electromagnetic radiation radiation of of frequency frequency 7.57.5 ×× 10 1099 Hz is directed towards a slit Hz is directed towards a slit
of width 6.0 cm. of width 6.0 cm.
ii Determine Determine the the wavelength wavelength of of the the radiation. radiation. [2][2] ii
ii Explain Explain whether whether or or not not the the radiation radiation will will be be diffracted diffracted at at the the slit. slit. [1][1] 7
7 Explain Explain what what is is meant meant byby coherentcoherentsources. sources. [1][1] 8
8 The diagram below shows the displacement–time graphs for two wavesThe diagram below shows the displacement–time graphs for two waves AA and andBB..
a
a What What is is the the phase phase difference difference between between the the two two waves? waves? [1][1] b
9
9 The diagram The diagram below shows an below shows an arrangement used arrangement used to demonstrate to demonstrate the interference othe interference of water waves.f water waves.
a
a Constructive interference occurs at pointConstructive interference occurs at point AA. What is the path difference of the waves from. What is the path difference of the waves from
the gaps
the gaps SS11 and andSS22? ? [1][1]
b
b The water The water waves have waves have a wavelength a wavelength of 3.0 of 3.0 cm. Determine cm. Determine the path the path difference fordifference for
the waves arriving at point
the waves arriving at point BB. . Name Name the the type type of of interference interference taking taking place place at at this this point. point. [3][3] 10
10 A microwave source is directed towards a metal plate with two narrow vertical slits. A receiverA microwave source is directed towards a metal plate with two narrow vertical slits. A receiver
is slowly moved along the line
is slowly moved along the line XYXY as shown in the diagram. as shown in the diagram.
a
a Explain Explain why why the the receiver receiver registers registers a a series series of of maxima maxima and and minima. minima. [3][3] b
b The wavelength of the microwaves is 2.8 cm. The separation between the slits is 4.0 cmThe wavelength of the microwaves is 2.8 cm. The separation between the slits is 4.0 cm
and the receiver is a distance of 80 cm from the slits. Calculate the separation between and the receiver is a distance of 80 cm from the slits. Calculate the separation between adjacent
adjacent maxima. maxima. [3][3]
c
c Describe the effect on your answer toDescribe the effect on your answer to bb when: when:
ii the the separation separation between between the the slits slits is is halved halved [1][1] ii
ii the the distance distance between between the the slits slits and and the the receiver receiver is is doubled. doubled. [1][1] 11
11 Monochromatic light is incident normally at a diffraction grating with 60 lines Monochromatic light is incident normally at a diffraction grating with 60 lines per mm.per mm.
The tenth-order maximum is observed at an angle of 19°. Determine: The tenth-order maximum is observed at an angle of 19°. Determine:
13
13 Blue Blue light light of of wavelength wavelength 4.54.5 ×× 10 10−−77 m is incident normally at a diffraction grating with m is incident normally at a diffraction grating with 100
100 lines lines per per mm. mm. Calculate Calculate the the maximum maximum number number of of orders orders that that can can be be observed. observed. [4][4]
14
14 Answer the Answer the following questions following questions with supporting with supporting calculations.calculations.
You are given a diffraction grating with 40 lines per mm. You are given a diffraction grating with 40 lines per mm.
a
a The diffraction The diffraction grating is grating is mounted mounted on an on an instrument that instrument that can measure can measure angles to angles to withinwithin ±±0.1°.0.1°.
Can this instrument be used to determine the individual wavelengths of spectral lines of Can this instrument be used to determine the individual wavelengths of spectral lines of wavelengths
wavelengths 589.6 589.6 nm nm and and 589.0 589.0 nm? nm? [6][6]
b
b White light White light is incident is incident normally at normally at the grating. the grating. Estimate the Estimate the angle between angle between the extremethe extreme
ends
ends of of the the spectrum spectrum for for the the tenth-order tenth-order maxima. maxima. [4][4]
Total: Total:
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