IB Physics Quiz: Technology
7 questions · exam conditions
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TechnologyQuestion 1 of 7

Modern digital cameras use sensors (like CCD or CMOS) while older cameras used photographic film. What is a key difference in the physical process by which these two technologies record an image?

Digital sensors convert photons directly into a storable electrical charge, whereas film relies on a photochemical reaction.
Digital sensors can capture color images in a single exposure, while film technology is only capable of black and white imaging.
Digital sensors have a fundamentally linear response to light intensity, whereas film's response is logarithmic.
Digital sensors are a passive technology that simply records incident light, while film actively emits light to create an image.
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IB Physics Quiz

IB Physics Quiz: Technology

Practice Technology in IB Physics with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.

What this quiz covers

This quiz focuses on Technology, giving you a quick way to practice the rules, question types, and explanations that matter most for IB Physics.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

All questions

Question 1

Modern digital cameras use sensors (like CCD or CMOS) while older cameras used photographic film. What is a key difference in the physical process by which these two technologies record an image?

  1. Digital sensors convert photons directly into a storable electrical charge, whereas film relies on a photochemical reaction. (correct answer)
  2. Digital sensors can capture color images in a single exposure, while film technology is only capable of black and white imaging.
  3. Digital sensors have a fundamentally linear response to light intensity, whereas film's response is logarithmic.
  4. Digital sensors are a passive technology that simply records incident light, while film actively emits light to create an image.
Explanation: The fundamental difference lies in the energy conversion process. A digital sensor's pixel is a photodiode that uses the photoelectric effect; an incident photon creates an electron-hole pair, and the accumulated charge in a pixel is proportional to the light intensity. This is a purely electronic process. Photographic film, on the other hand, is coated with an emulsion containing silver halide crystals. When a photon strikes a crystal, it initiates a chemical reaction that creates a latent image, which is then made visible through a chemical development process. A correctly identifies this electronic vs. photochemical distinction. B is incorrect as color film has existed for a long time. C is a valid but more nuanced difference; A is the most fundamental physical process distinction. D is incorrect as both are passive recording media.

Question 2

To improve the angular resolution of astronomical observations, multiple radio telescopes can be electronically linked to form an interferometer. This technology effectively creates a single virtual telescope with a much larger aperture. What physical limitation is this technology specifically designed to overcome?

  1. Atmospheric distortion, which causes the twinkling and blurring of astronomical images.
  2. The inverse square law, which causes the brightness of distant objects to decrease rapidly.
  3. The Doppler effect, which causes the spectral lines of distant galaxies to be shifted in wavelength.
  4. The diffraction limit, which sets a minimum resolvable angle proportional to the wavelength and inversely proportional to the aperture diameter. (correct answer)
Explanation: The ability of any telescope to resolve fine details (its angular resolution) is fundamentally limited by the diffraction of light. The Rayleigh criterion states that the minimum resolvable angle is approximately θ≈λ/D\theta \approx \lambda/D, where λ\lambda is the wavelength of light and DD is the diameter of the aperture. For radio waves, λ\lambda is very large, so a very large DD is needed for good resolution. Interferometry creates a virtual telescope with an effective diameter equal to the largest separation between the individual telescopes (the baseline), dramatically increasing DD and thus improving the resolution by overcoming the diffraction limit. A is addressed by adaptive optics. B relates to sensitivity (light-gathering power), not resolution. C is a phenomenon to be measured, not a limitation to be overcome.

Question 3

The development of higher-energy particle accelerators has been crucial for advances in particle physics. What is the primary physical reason why increasing the kinetic energy of colliding particles is a necessary technological step for discovering new, more massive particles?

  1. The de Broglie wavelength of the particles must be decreased to a scale smaller than the size of the new particles being investigated.
  2. Higher energy is required to overcome the strong nuclear force that binds quarks together within protons and neutrons.
  3. The kinetic energy of the colliding particles can be converted into the rest mass of new, massive particles according to the relation E=mc2E=mc^2. (correct answer)
  4. Higher energy allows particles to travel closer to the speed of light, where time dilation effects allow for the brief existence of new particles to be observed.
Explanation: Einstein's mass-energy equivalence principle, E=mc2E=mc^2, is the fundamental reason. To create a new particle with a large rest mass (m), a correspondingly large amount of energy (E) must be available. In a particle accelerator, this energy is supplied by the kinetic energy of the colliding particles. A is incorrect because while a smaller de Broglie wavelength is needed to probe smaller structures, it's the energy conversion that is required to create new massive particles. B is incorrect because while high energy is needed to probe sub-nuclear structures, the goal is often to create particles more massive than protons themselves. D is incorrect because while time dilation is an important relativistic effect for observing the decay of short-lived particles, it is not the reason high energy is needed for their creation.

Question 4

In stimulated emission, an excited atom emits a photon when triggered by an incoming photon of the same energy. What property of the emitted photon makes this process useful for producing laser light?

  1. High photon energy
  2. Coherent emission (correct answer)
  3. High speed of light
  4. Random polarization
Explanation: In stimulated emission, the emitted photon has the same energy, direction, phase, and polarization as the triggering photon. This creates coherent light where all photons are in phase, which is the key characteristic of laser light. The photon energy depends on the energy levels involved, all electromagnetic radiation travels at speed c in vacuum, and stimulated emission actually preserves polarization rather than randomizing it.

Question 5

Optical fibers are a technology used to transmit data over long distances using light pulses. The guidance of light within the fiber with very low loss relies on which physical phenomenon?

  1. Diffraction of light as it passes through the narrow core, which causes the beam to spread and fill the fiber.
  2. Total internal reflection at the boundary between a high-refractive-index core and a low-refractive-index cladding. (correct answer)
  3. Dispersion, where different wavelengths of light travel at slightly different speeds, allowing for signal multiplexing.
  4. Polarization of light by the glass material, which filters out unwanted signal noise and interference.
Explanation: An optical fiber consists of a central core made of glass with a certain refractive index (n_core) surrounded by a layer of cladding with a slightly lower refractive index (n_cladding). Light traveling in the core that strikes the core-cladding boundary at an angle greater than the critical angle will undergo total internal reflection. This means it is perfectly reflected back into the core and can propagate along the fiber for very long distances with minimal loss. A (diffraction) and C (dispersion) are actually phenomena that limit the performance of optical fibers, rather than enabling them. D (polarization) is relevant in some specialized fibers but is not the primary guiding principle.

Question 6

The operation of a Scanning Tunneling Microscope (STM) is based on which quantum mechanical phenomenon?

  1. The photoelectric effect
  2. Quantum tunneling (correct answer)
  3. The uncertainty principle
  4. Wave-particle duality
Explanation: A Scanning Tunneling Microscope works by exploiting quantum tunneling. Electrons tunnel across the vacuum gap between a sharp tip and a conducting surface, creating a current that depends exponentially on the gap width. This allows atomic-scale resolution. The photoelectric effect involves photon absorption, the uncertainty principle limits simultaneous measurement precision, and wave-particle duality describes the dual nature of matter and radiation, but none of these directly enable STM operation.

Question 7

In a thermal nuclear fission reactor, a moderator is a key technological component placed among the fuel rods. What is the primary function of the moderator in sustaining a controlled chain reaction?

  1. To absorb excess neutrons to prevent the chain reaction from becoming supercritical and running out of control.
  2. To transfer thermal energy from the reactor core to the heat exchanger for the purpose of generating steam.
  3. To slow down the fast neutrons produced by fission, increasing the probability they will be captured by other U-235 nuclei. (correct answer)
  4. To provide shielding for the reactor's surroundings from the harmful ionizing radiation produced during fission.
Explanation: Fission of Uranium-235 produces fast-moving neutrons. However, the probability of a neutron causing a subsequent fission in another U-235 nucleus (the fission cross-section) is much higher for slow-moving (thermal) neutrons. The moderator, typically a light material like water or graphite, is a substance that slows down the fast neutrons through collisions without absorbing them. This moderation is crucial for sustaining the chain reaction. A is the function of control rods (e.g., made of boron or cadmium). B is the function of the coolant (e.g., water). D is the function of the biological shield (e.g., thick concrete).