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Question 1: What is the boundary around a black hole from which nothing can escape?
- Singularity
- Event horizon
- Photon sphere
- Accretion disk
Answer: B. Event horizon
Explanation: The event horizon is the point of no return surrounding a black hole. Once anything crosses this threshold, the gravitational pull is too strong to escape.
Question 2: Which galaxy contains the supermassive black hole known as M87*?
- Sombrero
- Andromeda
- Messier 87
- Triangulum
Answer: C. Messier 87
Explanation: Messier 87, or M87, is a giant elliptical galaxy. It became famous in 2019 when the Event Horizon Telescope captured the first-ever image of its central black hole.
Question 3: What is the name of the black hole at the center of our Milky Way?
- V616 Monocerotis
- Sagittarius A*
- Centaurus A
- Cygnus X-1
Answer: B. Sagittarius A*
Explanation: Sagittarius A* is the supermassive black hole located at the very center of the Milky Way galaxy, around which all the stars in our galaxy orbit.
Question 4: What theoretical radiation is emitted by black holes due to quantum effects?
- Synchrotron radiation
- Bremsstrahlung
- Cosmic background
- Hawking radiation
Answer: D. Hawking radiation
Explanation: Proposed by Stephen Hawking, this radiation suggests that black holes are not completely black and can slowly lose mass and eventually evaporate over time.
Question 5: What phenomenon occurs when gravity bends light from a distant object?
- Redshift
- Gravitational lensing
- Refraction
- Parallax
Answer: B. Gravitational lensing
Explanation: Gravitational lensing happens when a massive object, like a galaxy or black hole, bends the light of a background object, acting like a cosmic magnifying glass.
Question 6: What is the dense core left behind after a massive star goes supernova?
- Brown dwarf
- White dwarf
- Neutron star
- Red dwarf
Answer: C. Neutron star
Explanation: When a massive star collapses, it can leave behind a neutron star, which is an incredibly dense object composed almost entirely of neutrons.
Question 7: What is the theoretical point of infinite density at a black hole's center?
- Singularity
- Event horizon
- Schwarzschild radius
- Ergosphere
Answer: A. Singularity
Explanation: The singularity is the center of a black hole where matter is crushed to an infinitely small point, resulting in infinite density according to general relativity.
Question 8: Which type of black hole is typically formed by the collapse of a single star?
- Supermassive
- Primordial
- Intermediate-mass
- Stellar-mass
Answer: D. Stellar-mass
Explanation: Stellar-mass black holes are created when massive stars run out of fuel and collapse under their own gravity, typically having 5 to 100 times the mass of our Sun.
Question 9: What instrument was used to capture the first image of a black hole?
- James Webb Telescope
- Hubble Telescope
- Event Horizon Telescope
- Kepler Space Telescope
Answer: C. Event Horizon Telescope
Explanation: The Event Horizon Telescope is a global network of synchronized radio observatories that worked together to image the shadow of the black hole in M87.
Question 10: What is the primary difference between a stellar-mass black hole and a supermassive one?
- The speed of rotation
- Mass and formation process
- The color of the accretion disk
- The presence of Hawking radiation
Answer: B. Mass and formation process
Explanation: Stellar-mass black holes form from the collapse of individual massive stars, while supermassive black holes contain millions to billions of solar masses and reside at galactic centers.