Dark Matter — MCQs

1. What is dark matter?
(A) Matter that emits visible light
(B) Matter that interacts only through gravity and possibly weak forces
(C) Ordinary matter in stars and planets
(D) Black holes and neutron stars only

2. What percentage of the universe’s total mass-energy is thought to be dark matter?
(A) 5%
(B) 27%
(C) 50%
(D) 68%

3. Which evidence first suggested the existence of dark matter?
(A) Gravitational lensing of quasars
(B) Galaxy rotation curves
(C) Cosmic microwave background
(D) Inflation theory

4. Who provided the earliest evidence for dark matter in the 1930s?
(A) Edwin Hubble
(B) Albert Einstein
(C) Fritz Zwicky
(D) Vera Rubin

5. Vera Rubin’s work on spiral galaxies showed that:
(A) Stars at the edges rotate faster than expected
(B) Dark matter emits X-rays
(C) Galaxies are slowing down
(D) Light bends away from galaxies

6. Dark matter does not interact significantly with:
(A) Gravity
(B) Electromagnetic radiation
(C) Large-scale structure formation
(D) Galaxy rotation

7. What is one leading candidate for dark matter particles?
(A) WIMPs (Weakly Interacting Massive Particles)
(B) Photons
(C) Electrons
(D) Neutrinos only

8. Axions are:
(A) Hypothetical particles that could explain dark matter
(B) A type of star
(C) Black holes
(D) Evidence against dark matter

9. MACHOs as dark matter candidates stand for:
(A) Massive Astrophysical Compact Halo Objects
(B) Magnetic And Chemical Halo Objects
(C) Matter And Cosmic Halo Observations
(D) Massive Atomic Core Halo Objects

10. Gravitational lensing provides evidence for dark matter by showing:
(A) Extra bending of light around galaxy clusters
(B) Increase in star brightness
(C) Acceleration of galaxies away from us
(D) Expansion of the universe

11. Which experiment is designed to detect WIMPs directly?
(A) LIGO
(B) Large Hadron Collider
(C) XENONnT experiment
(D) Kepler telescope

12. What role does dark matter play in galaxy formation?
(A) Slows down galaxy evolution
(B) Provides gravitational scaffolding for structure formation
(C) Prevents stars from forming
(D) Causes galaxies to collapse

13. The Bullet Cluster is strong evidence for dark matter because:
(A) Gas clouds move faster than galaxies
(B) Separation of visible matter and gravitational mass was observed
(C) Dark matter emits radio waves
(D) Galaxies disappeared during collision

14. Which force does dark matter primarily interact with?
(A) Gravity
(B) Electromagnetic force
(C) Strong nuclear force
(D) Weak nuclear force only

15. Which statement about dark matter is true?
(A) It glows in the infrared
(B) It is invisible but detectable through its gravitational effects
(C) It is composed of protons and neutrons only
(D) It makes up most of the universe’s energy

16. Neutrinos are sometimes considered a form of:
(A) Hot dark matter
(B) Cold dark matter
(C) Dark energy
(D) Antimatter

17. Cold dark matter is called “cold” because:
(A) It has no temperature
(B) Its particles move slowly compared to light speed
(C) It is found in cold regions of space
(D) It freezes hydrogen gas

18. Why are black holes unlikely to make up all dark matter?
(A) They emit visible light
(B) Their numbers and masses do not match observed effects
(C) They are too small
(D) They do not exist in galaxies

19. Which cosmic background measurement supports dark matter?
(A) Radio background
(B) Infrared background
(C) Cosmic microwave background (CMB)
(D) Gamma-ray background

20. Which model includes dark matter as essential for structure formation?
(A) Big Bang nucleosynthesis
(B) ΛCDM (Lambda Cold Dark Matter) model
(C) Inflationary model
(D) Steady-state theory

21. Dark matter helps explain:
(A) The expansion of the universe
(B) The large-scale clustering of galaxies
(C) The origin of black holes
(D) Solar system formation

22. The rotation curve of galaxies refers to:
(A) The orbit of planets
(B) The distribution of star velocities within galaxies
(C) Black hole rotation speed
(D) Expansion rate of space

23. Which type of dark matter is most favored by cosmology?
(A) Cold dark matter
(B) Hot dark matter
(C) Warm dark matter
(D) Visible dark matter

24. Which galaxy property is most affected by dark matter?
(A) Color
(B) Shape
(C) Rotation speed
(D) Chemical composition

25. Which observation of galaxy clusters supports dark matter?
(A) X-ray emissions from hot gas
(B) High orbital velocities of galaxies within clusters
(C) Presence of quasars
(D) Absence of stars in the center

26. What does the “missing mass problem” refer to?
(A) Lack of stars in galaxies
(B) Observed mass is insufficient to account for gravitational effects
(C) Neutron stars being too small
(D) Galaxies not colliding

27. Weak lensing refers to:
(A) Minor bending of light by dark matter distribution
(B) Strong bending of light near black holes
(C) Temporary dimming of stars
(D) Radiation scattering

28. Which property makes dark matter hard to detect?
(A) Strong nuclear interactions
(B) Lack of electromagnetic interaction
(C) High speed of particles
(D) Emission of X-rays

29. One indirect method to search for dark matter involves detecting:
(A) Light scattering
(B) Annihilation signals producing gamma rays
(C) Gravitational waves
(D) Ultraviolet flares

30. Which particle accelerator is used to search for dark matter?
(A) Tevatron
(B) Large Hadron Collider (LHC)
(C) Fermilab Booster
(D) RHIC

31. How does dark matter influence cosmic microwave background anisotropies?
(A) It erases them
(B) It enhances density fluctuations
(C) It reduces background temperature
(D) It creates gamma-ray bursts

32. Which kind of dark matter could explain galaxy formation at smaller scales?
(A) Warm dark matter
(B) Cold dark matter
(C) Hot dark matter
(D) Antimatter

33. The density profile of dark matter in galaxies is often modeled by:
(A) Kepler’s law
(B) Navarro-Frenk-White (NFW) profile
(C) Schrödinger equation
(D) Relativity equations

34. What makes hot dark matter unsuitable for galaxy formation?
(A) It decays too quickly
(B) Particles move too fast to form small structures
(C) It interacts strongly with radiation
(D) It emits visible light

35. Which astronomical survey mapped dark matter via weak lensing?
(A) Sloan Digital Sky Survey (SDSS)
(B) Gaia Mission
(C) Apollo missions
(D) Kepler Mission

36. What do computer simulations suggest about dark matter halos?
(A) They surround galaxies and stabilize them
(B) They exist only in black holes
(C) They are smaller than stars
(D) They do not affect galaxies

37. Which type of galaxy is most dark-matter dominated?
(A) Elliptical galaxies
(B) Spiral galaxies
(C) Dwarf galaxies
(D) Irregular galaxies

38. Why is dark matter not considered dark energy?
(A) Dark energy has no mass
(B) Dark energy drives expansion, dark matter drives structure formation
(C) Dark energy interacts with light, dark matter does not
(D) Dark matter is visible, dark energy is not

39. Modified Newtonian Dynamics (MOND) is proposed as:
(A) An alternative to dark matter hypothesis
(B) A way to detect WIMPs
(C) Evidence for MACHOs
(D) Dark energy measurement tool

40. What happens to galaxy clusters if dark matter is removed?
(A) They would disperse due to insufficient gravity
(B) They would remain unchanged
(C) They would form more stars
(D) They would collapse into black holes

41. How does dark matter influence gravitational lensing?
(A) Reduces bending of light
(B) Causes extra bending beyond visible mass contribution
(C) Eliminates lensing
(D) Creates only micro-lensing

42. Which future telescope aims to map dark matter more precisely?
(A) Roman Space Telescope
(B) Spitzer Telescope
(C) Hubble Space Telescope
(D) Parker Solar Probe

43. Which detection method relies on underground detectors?
(A) Direct detection of dark matter particles
(B) Cosmic ray measurement
(C) Gravitational waves
(D) CMB anisotropy studies

44. The missing satellites problem is related to:
(A) Too few observed dwarf galaxies compared to simulations
(B) Satellites not detecting signals
(C) Lack of radio galaxies
(D) Missing baryonic mass in stars

45. Self-interacting dark matter models suggest:
(A) Dark matter particles collide with each other
(B) Dark matter emits visible light
(C) Dark matter behaves like normal matter
(D) Dark matter explains cosmic inflation

46. Dark matter is crucial for explaining:
(A) Star temperature
(B) Distribution of galaxies in large-scale structure
(C) Orbital speed of planets
(D) Solar flares

47. Which is NOT a candidate for dark matter?
(A) WIMPs
(B) Axions
(C) Neutrinos
(D) Protons

48. Which detection strategy looks for dark matter annihilation?
(A) Gamma-ray telescopes
(B) Radio telescopes
(C) Neutrino detectors only
(D) Optical telescopes

49. Which large-scale experiment is built to study dark matter distribution?
(A) Large Synoptic Survey Telescope (LSST)
(B) James Webb Space Telescope
(C) Voyager spacecraft
(D) Hubble Space Telescope

50. The greatest mystery of dark matter is:
(A) Its temperature
(B) Its exact nature and particle identity
(C) Its visibility
(D) Its discovery date