plumiImaging and signalling: OCR A‑Level Physics B questions
Every OCR A-Level Physics B exam question on 3.1.1 Imaging and signalling, 2016–2025, with its mark scheme and examiner’s report.
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Calculations
![June 2025 Paper 1, question 3: What is the magnification of the image? A –167 B –0.0060 C +0.0060 D +167 [1] Your answer](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55701-jun25-03-qp.webp?v=3)
![June 2025 Paper 1, question 4: What is the focal length of the lens? A –3.02 cm B –2.98 cm C 2.98 cm D 3.02 cm [1] Your answer](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55701-jun25-04-qp.webp?v=3)
Q39(a)
The whole paper ↗![June 2025 Paper 1, question 39(a): Explain how the apparatus can be used to test if the microwaves from T are polarised vertically or horizontally. [2]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55701-jun25-39-a-qp.webp?v=3)
![June 2025 AS Paper 1, question 5: A typical value for the linear magnification achieved by a light microscope used in a secondary school is: 10–6 A 10–2 B 102 C 106 D Your answer [1]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h15701-jun25-05-qp.webp?v=3)
Q23(a)
The whole paper ↗![June 2025 AS Paper 1, question 23(a): Use the lens formula to show that the power of the lens is about +3D. 1 v = 1 u + 1 f [3]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h15701-jun25-23-a-qp.webp?v=3)
Q23(b)
The whole paper ↗
![June 2025 AS Paper 1, question 26(a): Suggest one advantage of having a digital, rather than analogue, output from the sensor. [1]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h15701-jun25-26-a-qp.webp?v=3)
![June 2025 AS Paper 1, question 26(b)(i): What is meant by the term amplitude? [1]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h15701-jun25-26-bi-qp.webp?v=3)
![June 2025 AS Paper 1, question 26(b)(ii): Calculate the number of bits required to encode 1024 levels. Number of bits required = bits [2]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h15701-jun25-26-bii-qp.webp?v=3)
![June 2025 AS Paper 1, question 26(c): The highest vibration frequency of interest is 2 kHz. Calculate the minimum number of samples that must be recorded per second. Number of samples = s–1 [2]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h15701-jun25-26-c-qp.webp?v=3)
![June 2024 Paper 1, question 3: What is the power of the lens? A 4 D B 5 D C 6 D D 7 D Your answer [1]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55701-jun24-03-qp.webp?v=3)
![June 2024 Paper 1, question 4: What is the length of the image? A 2.5 cm B 5.0 cm C 7.5 cm D 10.0 cm Your answer [1]](https://pub-e8a9dbab8e2a4d089f52b2a45e0d0b50.r2.dev/bank/h55701-jun24-04-qp.webp?v=3)
All 181 questions on Imaging and signalling, as a list
- June 2025, Paper 1, Q1 (1 mark): A rectangular digital image measures 1900 pixels by 1100 pixels. Each pixel is represented using 3 bytes. What is the total amount of information in this image?
- June 2025, Paper 1, Q3 (1 mark): What is the magnification of the image? A –167 B –0.0060 C +0.0060 D +167 [1] Your answer
- June 2025, Paper 1, Q4 (1 mark): What is the focal length of the lens? A –3.02 cm B –2.98 cm C 2.98 cm D 3.02 cm [1] Your answer
- June 2025, Paper 1, Q9 (1 mark): A car registration plate recognition camera is required to recognize 1 185 856 000 alternative values. How many bits are needed to store 1 185 856 000 alternati
- June 2025, Paper 1, Q39(a) (2 marks): Explain how the apparatus can be used to test if the microwaves from T are polarised vertically or horizontally. [2]
- June 2025, Paper 2, Q7 (3 marks): A scan of a phonoautogram (lines 18–28) produces a signal variation of 2 mV and a noise level of 75 μV. Calculate the number of bits to best represent this samp
- June 2025, AS Paper 1, Q2 (1 mark): The diagram shows two rays of light passing through a converging lens. z The distance z is called the: A Focal length B Focus C Image length D Power Your answer
- June 2025, AS Paper 1, Q4 (1 mark): An analogue signal has amplitude 80 mV and picks up noise of amplitude 5 mV. The number of useful quantisation levels needed to digitise this signal is equal to
- June 2025, AS Paper 1, Q5 (1 mark): A typical value for the linear magnification achieved by a light microscope used in a secondary school is: 10–6 A 10–2 B 102 C 106 D Your answer [1]
- June 2025, AS Paper 1, Q8 (1 mark): A student uses a microwave transmitter and receiver as shown in the diagram. receiver transmitter metal grille The microwaves from the transmitter are polarised
- June 2025, AS Paper 1, Q23(a) (3 marks): Use the lens formula to show that the power of the lens is about +3D. 1 v = 1 u + 1 f [3]
- June 2025, AS Paper 1, Q23(b) (3 marks): Light reflected from the tree is refracted as it passes through the lens. Draw wavefronts on the diagram below to show how the curvature of wavefronts is affect
- June 2025, AS Paper 1, Q26(a) (1 mark): Suggest one advantage of having a digital, rather than analogue, output from the sensor. [1]
- June 2025, AS Paper 1, Q26(b)(i) (1 mark): What is meant by the term amplitude? [1]
- June 2025, AS Paper 1, Q26(b)(ii) (2 marks): Calculate the number of bits required to encode 1024 levels. Number of bits required = bits [2]
- June 2025, AS Paper 1, Q26(c) (2 marks): The highest vibration frequency of interest is 2 kHz. Calculate the minimum number of samples that must be recorded per second. Number of samples = s–1 [2]
- June 2025, AS Paper 1, Q26(d) (2 marks): A different sensor generates 15 bits per sample and 8000 samples per second. The output data is transmitted to a computer system using a wireless network. An ad
- June 2024, Paper 1, Q2 (1 mark): Which statement about ultrasound is correct? A Ultrasound can be diffracted and polarised. B Ultrasound can be diffracted but cannot be polarised. C Ultrasound
- June 2024, Paper 1, Q3 (1 mark): What is the power of the lens? A 4 D B 5 D C 6 D D 7 D Your answer [1]
- June 2024, Paper 1, Q4 (1 mark): What is the length of the image? A 2.5 cm B 5.0 cm C 7.5 cm D 10.0 cm Your answer [1]
- June 2024, Paper 1, Q32(a) (2 marks): Fig. 32.1 shows the signal given to the students. Fig. 32.1 6 5 4 signal 3 level / mV 2 1 0 0 1 2 3 4 5 6 time / ms The students: • sample the signal every mill
- June 2024, Paper 1, Q32(b) (2 marks): Fig. 32.3 shows another signal given to the student. Fig. 32.3 6 5 4 signal 3 level / mV 2 1 0 0 1 2 3 4 5 6 time / ms Explain why, when this signal is digitise
- June 2024, Paper 2, Q8(b)(i) (2 marks): Suggest why the camera is designed to resolve to a smaller angle than that calculated in (a). image resolution = rad pixel–1 Suggestion: [2]
- June 2024, Paper 3, Q3(a) (2 marks): Measurements of u and v are recorded in Table 3.1. Complete the table by calculating the missing values of 1 u and 1 v . Table 3.1 1 1 /m–1 /m–1 u / m v / m u v
- June 2024, Paper 3, Q3(c) (3 marks): Determine a value for the focal length of the lens. Use your line on the graph. focal length = m [3] 11 Fig. 3.2
- June 2024, Paper 3, Q3(d) (6 marks): Describe the sources of uncertainties and the limitations of this method to find the focal length of a lens. Describe and explain methods to improve the experim
- June 2024, AS Paper 1, Q4 (1 mark): A spacecraft takes an image of Saturn’s moon Enceladus. The image of the full moon fills the imaging sensor which has diameter 5 mm. The moon’s diameter is 500
- June 2024, AS Paper 1, Q5 (1 mark): An automatic number plate recognition (ANPR) system identifies cars by reading the number plate from a camera image. Which image processing technique can be use
- June 2024, AS Paper 1, Q7 (1 mark): A student is using a microwave transmitter and receiver as shown in the diagram. receiver transmitter meter metal grille The student notices the reading on the
- June 2024, AS Paper 1, Q22(a)(i) (1 mark): the number of levels Number of levels = [1]
- June 2024, AS Paper 1, Q22(a)(ii) (1 mark): the number of bits required to encode the signal Number of bits = [1]
- June 2024, AS Paper 1, Q22(a)(iii) (1 mark): the time between samples. Time = μs [1]
- June 2024, AS Paper 1, Q22(b) (2 marks): The quality of the digital signal will be acceptable if the minimum sampling rule is met: minimum rate of sampling > 2 × maximum frequency of signal Show whethe
- June 2024, AS Paper 2, Q1(a)(i) (1 mark): Fig. 1.2 is a graph of the light intensity registered by the detector against the angle of rotation of polaroid Q from its initial position. Fig. 1.2 intensity
- June 2024, AS Paper 2, Q1(a)(ii) (1 mark): What characteristic of a light wave allows it to be polarised? [1]
- June 2024, AS Paper 2, Q1(b) (2 marks): Fig. 1.3 shows two rays and three wave-fronts in a beam of light that is incident on a thin converging lens. The focal length of the lens is f. Fig. 1.3 f ray r
- June 2023, Paper 1, Q11 (1 mark): A signal is recorded. The total amplitude of the signal voltage varies from zero to 2.56 mV. The noise in the signal is 2.5 × 10–3 mV. The highest frequency com
- June 2023, Paper 1, Q13 (1 mark): A pencil of length 0.15 m is placed 1.20 m from a lens of power +5.00 D and forms a clear image. What is the length of the image of the pencil? A 0.02 m B 0.03
- June 2023, Paper 1, Q31(a) (1 mark): Electromagnetic waves can be polarised. State the difference between a polarised and an unpolarised wave. [1]
- June 2023, Paper 1, Q31(b) (2 marks): It is suggested that visible light is partially polarised when it is reflected. Describe how you can use a polarising filter to determine if this suggestion is
- June 2023, Paper 1, Q32(a)(i) (1 mark): Calculate the number of bits in a single image uploaded from the webcam. number = bits [1]
- June 2023, Paper 1, Q32(a)(ii) (1 mark): The number of bits per image is reduced by a process called compression. The camera captures 30 images each second. A recording of a 40-minute lesson is uploade
- June 2023, Paper 1, Q32(b) (2 marks): A second camera has a greater number of pixels. The teacher decides not to use this camera for streaming lessons. Suggest two reasons for this decision. 1 2 [2]
- June 2023, Paper 2, Q6(a)(i) (1 mark): What feature of Fig. 6.1 shows that the object producing the wavefronts is a long way from the lens? [1]
- June 2023, Paper 2, Q6(a)(ii) (1 mark): Add wavefronts to the right of the lens which focus at point P. [1]
- June 2023, Paper 2, Q6(a)(iii) (2 marks): The lens adds curvature of +1.8 D to the waves. Calculate the distance from the lens to point P. Explain your reasoning. distance to P = m Reasoning: [2]
- June 2023, Paper 2, Q6(b)(ii) (2 marks): Explain why the power of the lens will be greater for shorter wavelength light and the effect this will have on the focal length of the lens for light of differ
- June 2023, Paper 2, Q6(c)(i) (2 marks): This letter X is approximately 4 mm high. Calculate the height of the image of the X on the retina of a person with normal vision when viewed from the near poin
- June 2023, Paper 2, Q6(c)(ii) (2 marks): Calculate the power of a lens required to allow a person with a near point of 50 cm to focus an object at a distance of 25 cm. lens power = D [2]
- June 2023, Paper 2, Q6(d) (3 marks): Here are some data about two materials used for spectacle lenses. density / kg m–3 material refractive index 3.2 × 103 high-index glass 1.70 1.2 × 103 plastic (
- June 2023, AS Paper 1, Q2 (1 mark): A sound wave has frequency 440 Hz. The speed of sound in air is 330 m s–1. The wavelength of 2 the sound wave is: A 75 cm B 125 cm C 1.45 m D 75 m Your answer [
- June 2023, AS Paper 1, Q7 (1 mark): In a plane-polarised light ray, the oscillations in the electric field are: A In all directions, perpendicular to the direction of propagation B In one plane, p
- June 2023, AS Paper 1, Q17 (1 mark): A detector receives a signal of constant amplitude carried by a plane-polarised wave. Which answer describes a possible sequence of amplitude measurements when
- June 2023, AS Paper 1, Q25(a) (2 marks): Show that the focal length of the lens is approximately 4 cm. [2] The diagram below shows wavefronts from an object in front of the dashcam incident on the lens
- June 2023, AS Paper 1, Q25(b) (2 marks): Add to the diagram to show the wavefronts between the lens and the sensor. [2] 17 The dashcam requires a memory card to store the video it captures. The dashcam
- June 2023, AS Paper 1, Q25(c) (2 marks): How many bits per pixel are required to resolve over 16 million different colours? bits per pixel = [2] The dashcam records 22 frames of video per second and co
- June 2023, AS Paper 1, Q25(d) (3 marks): Show that no more than 21 minutes of video could be stored on a 64 GB memory card. [3]
- June 2023, AS Paper 2, Q7(a)(ii) (2 marks): Describe and explain the feature of Fig. 7.1 which shows that this musical note contains more than one frequency. [2]
- June 2023, AS Paper 2, Q7(b)(i) (3 marks): Explain how the eight voltage levels illustrated can be encoded with a three-bit binary number and give the binary code which would represent a value of 3 mV. b
- June 2023, AS Paper 2, Q7(b)(ii) (2 marks): Explain why the audio signal produced from this code will sound different from the original clarinet note. [2]
- June 2023, AS Paper 2, Q7(c) (2 marks): A piece of music for solo clarinet lasts for 1 minute and 39 seconds. Assuming that it is digitised with eight voltage levels (3-bit coding) sampled every 0.25
- June 2023, AS Paper 2, Q7(d) (2 marks): A commercial download of the music described in (c) is a stereophonic (two-channel) recording sampled at 44.1 kHz with 8-bit coding. Calculate the time taken to
- June 2022, Paper 1, Q1 (1 mark): In an experiment to determine the focal length of a converging lens, a student sets up the apparatus shown in the diagram and observes a clear image on the scre
- June 2022, Paper 1, Q2 (1 mark): A light sensitive microchip in a camera has 3.2 × 109 pixels. Each pixel records intensity level 2 with 12 bits. How much information can be stored per image? A
- June 2022, Paper 1, Q3 (1 mark): The diagram shows how the wavefronts and rays leave a converging lens. The focal length of the lens is f and the distance between the object that produced the w
- June 2022, Paper 1, Q4 (1 mark): The variation of a signal without noise is 140 mV. The maximum number of useful bits to sample the same signal with noise is 3. What is the noise variation in t
- June 2022, Paper 1, Q7 (1 mark): A sound signal with a highest frequency component of 8 kHz is digitised. The signal to noise ratio of the recording is 103. Which row in the table below gives t
- June 2022, Paper 3, Q1(a) (2 marks): Explain what is meant by the term polarisation and state why all electromagnetic waves can be polarised. [2]
- June 2022, Paper 3, Q1(b) (3 marks): A student looks at light reflected from a glass block through one polarising filter. Explain how they could tell if the reflected light shows any polarisation.
- June 2022, Paper 3, Q1(c)(i) (2 marks): Describe how the angle of rotation could be measured in a school laboratory. [2]
- June 2022, Paper 3, Q1(c)(ii) (3 marks): The results from the investigation are plotted on the graph shown in Fig. 1.2. Use data points from the graph below (excluding voltage = 0) to test whether the
- June 2022, AS Paper 1, Q10 (1 mark): From which of these can you determine the power of a thin converging lens? A diameter B focal length C image distance D magnification Your answer [1]
- June 2022, AS Paper 1, Q18 (1 mark): A signal is received with a signal-to-noise ratio of 7.5. Which is the best choice of the number of bits used to sample this signal? A 2 B 3 C 7 D 8 Your answer
- June 2022, AS Paper 1, Q25(a) (1 mark): Determine the number of different shades of grey that can be represented by 8 bits. number of shades = [1]
- June 2022, AS Paper 1, Q25(b) (2 marks): Calculate the time taken to transmit this image at a rate of 54 megabits per second. time taken = s [2]
- June 2022, AS Paper 1, Q25(c) (4 marks): The virus particles are approximately 100 nm in diameter. Determine the approximate resolution of the image in metres per pixel. Give your answer to 2 significa
- June 2022, AS Paper 1, Q25(d) (2 marks): The original image was enhanced before publication on the internet. Suggest two ways in which this image might have been enhanced. 1 2 [2]
- June 2022, AS Paper 2, Q2(a) (2 marks): Calculate the ratio fsound . fradio fsound = [2]
- June 2022, AS Paper 2, Q2(b) (1 mark): A more complex sound signal is a sum of musical notes with a frequency range 18 Hz to 24 kHz. It is to be encoded as a digital signal before transmission. Calcu
- June 2022, AS Paper 2, Q4(a) (2 marks): Calculate the power P of the lens. P = D [2]
- June 2022, AS Paper 2, Q4(b) (3 marks): The diagram below shows the light ray in region A. Two wavefronts to the left of the lens are shown. Draw wavefronts on this diagram to show how the shape and s
- June 2022, AS Paper 2, Q6(b)(i) (2 marks): The CCD sensor in each camera consists of an array of square pixels. There are 1600 × 1200 square pixels in an area of 1.05 × 10–4 m2. Show that the length of a
- June 2022, AS Paper 2, Q6(b)(ii) (2 marks): When the camera records an image of a distant object, the image distance v from the lens to the CCD sensor is 19.5 mm. Show that the camera can resolve two poin
- June 2022, AS Paper 2, Q6(b)(iii) (2 marks): The full-colour images recorded by each camera are encoded at 11 bits pixel–1. Suggest why more than 8 bits pixel–1 are needed and calculate the number of image
- June 2022, AS Paper 2, Q6(b)(iv) (6 marks): This question is about using remote sensors to make measurements on the planet Mars. (iv)* As much of the data recorded by Perseverance on its 8 Gb memory unit
- November 2021, Paper 1, Q2 (1 mark): The camera in a smartphone contains a CCD detector of 1136 pixels × 640 pixels. Each pixel records in full RGB colour, encoded into three bytes of memory. How m
- November 2021, Paper 1, Q5 (1 mark): Which adjustments need to be made to produce a more magnified image? Screen Lens A closer to the lens closer to the slide B closer to the lens further from the
- November 2021, Paper 1, Q6 (1 mark): The power of the projecting lens in dioptres, D is A 0.040 B 0.071 C 25.0 D 25.1 Your answer [1]
- November 2021, Paper 1, Q32(a) (1 mark): Explain why the sampling frequency should be at least 25 kHz. [1]
- November 2021, Paper 1, Q32(b) (2 marks): Suggest and explain the number of bits per sample you would use to digitise this waveform. [2]
- November 2021, Paper 2, Q8(a) (2 marks): Calculate the resolution of the image. resolution = mm [2]
- November 2021, Paper 2, Q8(b) (2 marks): The image size is 644 000 bits. Explain why this suggests that each pixel in the image is either white or black and suggest how the image appears to show shades
- November 2021, AS Paper 1, Q2 (1 mark): Each pixel in an image is one of 65 000 different colours. How many bits are required to store the colour information for each pixel? A 5 B 12 C 15 D 16 Your an
- November 2021, AS Paper 1, Q6 (1 mark): Which of these is a benefit of digital signals over analogue signals? A Amplifying a digital signal boosts the signal and noise. B Digital signals never need to
- November 2021, AS Paper 1, Q7 (1 mark): A source of plane-polarised light of intensity A0 is viewed through a polarising filter. The axis of the filter is perpendicular to the axis of polarisation of
- November 2021, AS Paper 1, Q24(a) (2 marks): Calculate the curvature of the wavefront on the right of the lens. curvature = m–1 [2] The candle is moved further away from the lens (to the left) and the imag
- November 2021, AS Paper 1, Q24(b) (1 mark): State how to move the card to re-focus the image. [1]
- November 2021, AS Paper 1, Q24(c) (2 marks): Describe two differences in the appearance of this image compared to the original image. 1 [1] 2 . [1]
- November 2020, Paper 1, Q2 (1 mark): A real image is formed by a lens of power 20 D. Which statement is correct? A All wavefronts passing through the lens have a final curvature of 20 D. B The foca
- November 2020, Paper 1, Q3 (1 mark): Quantisation errors can best be reduced by A decreasing the bits per sample. B decreasing the sampling frequency. C increasing the sampling frequency. D increas
- November 2020, Paper 1, Q4 (1 mark): The bit rate (bits s−1) of the digitised sample is: 4 A 3 B 30 C 1110 D 3000 Your answer [1] 4 The following information is for use in questions 5 and 6. A B C
- November 2020, Paper 1, Q36(a)(i) (1 mark): Show that the information rate needed for this digitisation during playback is greater than 1 Mbit s−1. [1]
- November 2020, Paper 1, Q36(a)(ii) (2 marks): A CD typically stores 840 MBytes. Show that the total playback time is about 80 minutes for such a CD. time = minutes [2]
- November 2020, Paper 1, Q36(b)(i) (1 mark): State the evidence from Fig. 36.1 that there is more than one frequency present in the waveform. [1] 26 A sound spectrum displays the different frequencies pres
- November 2020, Paper 1, Q36(b)(ii) (1 mark): Suggest why it is possible to ignore signals of under about 5 mV. [1]
- November 2020, Paper 1, Q36(b)(iii) (1 mark): Some humans have perfect pitch judgement for sound, accurate to ± 1 Hz. Calculate the minimum number of bits needed to code for this precision for the frequency
- November 2020, Paper 1, Q36(b)(iv) (2 marks): To digitise this 10 ms sample of the sound wave each of the four peaks in the sound spectrum of Fig. 36.2 can be coded by 24 bits. Show that the minimum rate of
- November 2020, Paper 2, Q4(a) (1 mark): The lens system of the camera acts like a single lens of focal length 3.85 mm. Calculate the curvature added to waves when they pass through the lens. curvature
- November 2020, Paper 2, Q4(b) (2 marks): Use ideas about curvature of waves to explain why the lens cannot form an image of an object closer than or equal to 3.85 mm from the lens. [2]
- November 2020, Paper 2, Q4(c) (3 marks): The light-sensitive surface in the camera is fixed 3.85 mm behind the lens. The image recorded on this surface will be clear if the true position of the image i
- November 2020, Paper 2, Q4(d) (2 marks): The camera is used to form an image of a resin chess piece Fig. 4 a. The chess piece is 0.090 m long. It is 0.35 m from the lens. Image recorded by camera Proce
- November 2020, Paper 2, Q4(e) (4 marks): There are 12 × 106 square pixels on the rectangular light-sensitive surface. The dimensions of the surface are 4.89 mm × 3.65 mm. Use these data and your answer
- November 2020, Paper 2, Q4(f) (4 marks): The image in Fig. 4 b has been processed. Identify a change that has been made in the image and explain how the data producing the image has been altered. Expla
- November 2020, Paper 2, Q7(b) (3 marks): State the minimum sampling frequency required to accurately digitise the waveform. Explain your answer. minimum sampling frequency = Hz Explanation: [3]
- November 2020, AS Paper 1, Q1 (1 mark): Which method of image manipulation could be used to show different temperatures in an infra-red image? A edge detection B enhanced contrast C false colour D noi
- November 2020, AS Paper 1, Q5 (1 mark): The diagram shows an analogue signal. V t Which diagram best represents the signal sampled using 3 bits? A B V V t t C D V V t t Your answer [1]
- November 2020, AS Paper 1, Q21(a) (1 mark): How many bits are required to distinguish the 256 shades? number of bits = [1]
- November 2020, AS Paper 1, Q21(b) (2 marks): Calculate the amount of information in the image, in kilobytes. information = kB [2]
- November 2020, AS Paper 1, Q26(a) (1 mark): Describe what the student would observe as he rotates the filter. [1] The student uses the unpolarised light source to illuminate the surface of a glass block.
- November 2020, AS Paper 1, Q26(b) (2 marks): Describe how the meter reading changes as the angle of incidence increases from 50° to 70°. [2] The angle at which the meter reading is zero is called the Brews
- November 2020, AS Paper 1, Q26(c) (1 mark): Estimate the Brewster angle from the graph. Brewster angle ≈ ° [1]
- November 2020, AS Paper 1, Q26(d) (2 marks): Explain what the student can deduce about the reflected light at this angle. [2] 20 The student wants to find a more precise value for the Brewster angle. He re
- November 2020, AS Paper 2, Q3(a) (3 marks): Explain why using 9-bit quantisation to sample the signal is not better than using 8-bit quantisation. Justify your answer with an appropriate calculation. [3]
- November 2020, AS Paper 2, Q3(b) (2 marks): The signal consists of two stereo channels, each sampled with 8-bit quantisation as stated in part (a). The sampling rate is 44.1 kHz. Calculate the rate of tra
- June 2019, Paper 1, Q5 (1 mark): A slide projector has a lens of focal length f. It is set up to give a large, magnified focused image on a screen. The screen is further than 2 f from the lens
- June 2019, Paper 1, Q8 (1 mark): A signal is digitised by sampling at 22 kHz. The total voltage variation is 2.0 V and the noise voltage variation is 1.0 mV. Which statement is correct? A The h
- June 2019, Paper 1, Q36(a)(ii) (1 mark): State an advantage that the response of the detector D has over that of the film F. [1]
- June 2019, Paper 1, Q36(a)(iii) (2 marks): For detector D the relative intensity is the pixel value. Show that 14 bits per pixel are enough to cover the range of intensities plotted. [2]
- June 2019, Paper 1, Q36(b)(i) (2 marks): The image format is 2048 × 1680 pixels with 4096 greyscale levels. Calculate the amount of memory in bits needed to store an uncompressed image. memory required
- June 2019, Paper 1, Q36(b)(ii) (1 mark): During image processing the radiologist interpreting the image can stretch the contrast of the bone structures (whiter parts of image) more than the darker regi
- June 2019, Paper 1, Q36(b)(iii) (1 mark): Identify one process (other than contrast improvement) that has been applied to the image in Fig. 36.2 to produce the enhanced image in Fig. 36.3. Suggest the b
- June 2019, Paper 2, Q7 (2 marks): Fig. 7.1 is an image from Mariner 9. It shows most of the crater at the top of Olympus Mons. 832 pixels 700 pixels 70 km 70 km 70 km Fig. 7.1 Use data from Fig.
- June 2019, AS Paper 2, Q8(c) (2 marks): Show that the lens equation for a converging lens of power P should result in a straight-line graph with gradient 1 and y-axis intercept P if 1 v is plotted on
- June 2018, Paper 1, Q3 (1 mark): How many bits are required to code for 1300 different levels? A 3 B 4 C 10 D 11 Your answer [1]
- June 2018, Paper 1, Q4 (1 mark): An image sent from Pluto to Earth is 1024 # 1024 pixels. Each pixel is coded by 12 bits. The data is transferred at a rate of 200 bytes per second. How long doe
- June 2018, Paper 1, Q31(a) (3 marks): Calculate the power of the lens. power of the lens = D [3]
- June 2018, Paper 1, Q31(b) (1 mark): State the magnification of the lens in this example. magnification = [1]
- June 2018, Paper 1, Q32(a) (2 marks): Show that the time taken for the file to download is greater than 6 minutes. [2]
- June 2018, Paper 1, Q32(b) (2 marks): The video file contains a soundtrack sampled at 16.0 kHz. State and explain the highest frequency of sound that can be recorded on the soundtrack. highest frequ
- June 2018, Paper 2, Q1(a) (2 marks): A student takes two polarising filters as shown in Fig. 1.1. Unpolarised light is incident on the filter 1. Filter 2 is initially set up to allow all the light
- June 2018, AS Paper 1, Q12 (1 mark): A converging lens produces a focused image at a distance of 0.40 m from the lens. The magnification of the image is 2.0. What is the power of the lens? A 0.13 D
- June 2018, AS Paper 1, Q24(a) (1 mark): State the minimum rate of sampling that should be used. minimum sampling rate = Hz [1]
- June 2018, AS Paper 1, Q24(b) (2 marks): In this system the = 3000. noise variation Calculate the number of bits that should be used per sample for this system. number = bits [2]
- June 2018, AS Paper 1, Q27(a)(i) (1 mark): The image is 1024 × 711 pixels. The original data transmitted for this image was 5.8 Mbits. Calculate the number of bits per pixel in the original data. bits pe
- June 2018, AS Paper 1, Q27(a)(ii) (1 mark): The 5.8 Mbits was downloaded to an Earth receiver at a rate of 110 kbit s−1. Calculate the time taken to download this data. time taken = s [1]
- June 2018, AS Paper 1, Q27(b)(i) (3 marks): Two radii of the moon Enceladus have been added to Fig. 27.1. The resolution of the image is 330 m per pixel. Show that the diameter of Enceladus is less than 5
- June 2018, AS Paper 1, Q27(b)(ii) (2 marks): The image was taken with a sensor of square pixels of width 5 μm. Fig. 27.2 shows the formation of this image (not to scale). CCD lens Enceladus (not to scale)
- June 2018, AS Paper 2, Q1(a) (2 marks): Calculate the power P of the combination of the cornea and the lens. P = D [2]
- June 2018, AS Paper 2, Q1(b) (2 marks): The sensitive cells at the centre of the retina are separated by 2.5 μm. Calculate the distance d on the book that would correspond to this separation in the im
- June 2018, AS Paper 2, Q1(c) (2 marks): A long-sighted person cannot focus on an object 25 cm from the eye. Carol is long-sighted and the closest object that forms a sharp image on her retina is 1.5 m
- June 2018, AS Paper 2, Q2(a) (2 marks): Each pixel is encoded by 3 bytes, one for each of the colours red, green and blue. A new image is displayed on the screen 30 times each second. Calculate the nu
- June 2018, AS Paper 2, Q2(b) (2 marks): When this one-hour high-definition video is downloaded, it takes up 13 GB on the digital storage. This value is much smaller than the value calculated in (a). S
- June 2017, Paper 1, Q4 (1 mark): A signal is being digitised by sampling at 12 kHz. The total voltage is 5.0 V and the noise voltage is 4.9 mV. Which statement is correct? V total 3 A 10 . V no
- June 2017, Paper 2, Q4(b)(i) (3 marks): Calculate the resolution of the image in km pixel –1. resolution = km pixel–1 [3]
- June 2017, Paper 2, Q4(b)(ii) (4 marks): The image in Fig. 4.1a was taken at a distance of 770 000 km. The angular resolution of LORRI is 5 × 10–6 radian per pixel. This means that each pixel covers an
- June 2017, Paper 3, Q4(b)(i) (2 marks): The last two points from Fig. 4.2 have not been plotted. Complete Fig. 4.5 below, adding the last two magnification values. u / m v / m m −0.225 0.480 −0.200 0.
- June 2017, Paper 3, Q4(b)(iii) (2 marks): Use v to show that m + . 1 = + =- u f f [2]
- June 2017, Paper 3, Q4(b)(iv) (2 marks): Use data from the graph to calculate the focal length f of the lens. f = m [2]
- June 2017, Paper 3, Q4(c)(i) (1 mark): Use Fig. 4.6 to determine the power of this lens. Power = dioptre [1]
- June 2017, AS Paper 1, Q5 (1 mark): A spacecraft sends images of Pluto to Earth. Each image consists of 1024 × 1024 pixels. Each pixel is coded by 12 bits. The data transfers at a rate of 200 byte
- June 2017, AS Paper 1, Q7 (1 mark): A plane-polarised light wave is passed through a single polarising filter. The filter is rotated and the intensity observed drops from a maximum to zero. Throug
- June 2017, AS Paper 1, Q8 (1 mark): The graphs below describe a sound wave. P, Q and R are intervals of time or distance as indicated on the graphs. displacement / m displacement / m P R Q Q time
- June 2017, AS Paper 1, Q22 (3 marks): The lens in a digital camera has focal length, f = 2.0 cm. The camera is used to take a picture of a cat that is 50 cm away. Calculate the distance between the
- June 2017, AS Paper 1, Q27(a) (3 marks): Explain how this signal can be digitised. You may draw on Fig. 27.1 to support your answer. �������������������������������������������������������������������
- June 2017, AS Paper 1, Q27(b)(iii) (2 marks): Use the data to estimate the number of bits stored in the file per second of sound recorded. bits per second = [2]
- June 2017, AS Paper 2, Q7(a)(i) (2 marks): State how this fact shows that each pixel was encoded by one byte (8 bits) of data. [2]
- June 2017, AS Paper 2, Q7(a)(ii) (2 marks): Radiation from the Sun affected the cameras in the probe, changing the values of some pixels, so the photograph of Fig. 7.1 was severely affected by noise. Fig.
- June 2017, AS Paper 2, Q7(b) (2 marks): Fig. 7.2 is a magnified view of part of Fig. 7.1. 25 km Fig. 7.2 13 Use Fig. 7.2 to estimate the resolution of the surface of Mercury in this image. Show your w
- June 2017, AS Paper 2, Q7(c) (4 marks): The data generating Fig. 7.1 was processed by computer to give the image shown in Fig. 7.3. Fig. 7.3 Removal of noise has both advantages and disadvantages. Sug
- June 2017, AS Paper 2, Q7(d) (3 marks): The data for the image in Fig. 7.1 was sent from the Mariner space probe back to Earth at a rate of 117.6 kilobits s−1. The complete image was transmitted in 22
- June 2016, AS Paper 1, Q6 (1 mark): Waves from an object 0.5 m away pass through a lens of focal length 0.2 m. Which of the following give the curvature of the waves entering the lens and leaving
- June 2016, AS Paper 1, Q7 (1 mark): The display of a laptop screen is viewed through a polarising filter by a student. The intensity of the light changes when the filter is rotated. Which property
- June 2016, AS Paper 1, Q22(a) (1 mark): Explain the term polarised. [1]
- June 2016, AS Paper 1, Q22(b) (1 mark): The transmitter T faces the receiver R as shown in Fig. 22. The signal received is a maximum. T R Fig. 22 State what happens to the intensity of the signal rece
- June 2016, AS Paper 1, Q23(a) (2 marks): Determine the number of bits per sample that have been used to digitise the signal. Explain your reasoning. number of bits per sample = [2]
- June 2016, AS Paper 1, Q23(b) (1 mark): Estimate the frequency of the analogue signal shown in Fig. 23. Make your method clear. frequency = Hz [1]
- June 2016, AS Paper 2, Q1(a) (1 mark): Show that the power of the lens is 250 D. [1]
- June 2016, AS Paper 2, Q1(b)(i) (3 marks): Show that the lens needs to move less than 0.1 mm from its original position, 4.0 mm from the CCD detector, to give a sharp image of the object page. [3]
- June 2016, AS Paper 2, Q1(b)(ii) (2 marks): Explain why a letter 3 mm long on the object page, 24 cm from the lens, will result in an image on the CCD detector which is about 0.05 mm long. [2]
- June 2016, AS Paper 2, Q1(b)(iii) (2 marks): The 5 megapixel CCD detector in the camera is shown in Fig. 1. Calculate the distance in mm on the object page corresponding to 1 pixel on the detector. 6.4 mm
- June 2016, AS Paper 2, Q1(b)(iv) (2 marks): Here is an equation printed on the object page: ⎛ ⎞ Vtotal b = log2 . ⎜ ⎟ Vnoise ⎝ ⎠ It is the same size on this examination paper as it is on the object page.
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