- 1. Stellar evolution is the process by which a star changes over the course of its life. It starts with the collapse of a giant molecular cloud composed mostly of hydrogen and helium gas. As gravity pulls the gas and dust together, the temperature and pressure at the core of the cloud increases until nuclear fusion reactions ignite, initiating the star's main sequence phase. During this stage, a star generates energy by fusing hydrogen into helium in its core. Eventually, the star runs out of hydrogen fuel and begins to evolve into a red giant by expanding and cooling. Depending on the star's initial mass, it can undergo further stages of fusion, fusing heavier elements in its core. This can result in the formation of neutron stars, black holes, or planetary nebulae. Stars continue to change and evolve until they reach the end of their life cycle, which varies depending on their mass and composition. Stellar evolution provides valuable insights into the life cycle of stars and the formation of elements in the universe.
What is the final stage in the life cycle of a low to medium-mass star, like our Sun?
A) White dwarf
B) Supernova
C) Neutron star
D) Black hole
- 2. When a massive star exhausts its nuclear fuel, what catastrophic event may occur?
A) Supernova
B) Red giant explosion
C) Planetary nebula
D) Black hole formation
- 3. Which type of star is known for pulsating in size and luminosity due to instability in its core?
A) Cepheid variable
B) Neutron star
C) Red giant
D) Brown dwarf
- 4. What is the endpoint of stellar evolution for stars several times more massive than the Sun?
A) Supernova
B) Black hole
C) White dwarf
D) Red supergiant
- 5. Which region of a star is responsible for outward pressure balancing gravity inward?
A) Photosphere
B) Chromosphere
C) Corona
D) Core
- 6. Which of the following is a key factor influencing a star's evolution?
A) Mass
B) Color
C) Age
D) Distance
- 7. Which mechanism prevents a white dwarf star from continuing to collapse under gravity?
A) Gravitational lensing
B) Nuclear fusion
C) Hawking radiation
D) Electron degeneracy pressure
- 8. What is the term for the balance between the inward pull of gravity and the outward push of pressure in a star?
A) Tidal heating
B) Nuclear fusion
C) Orbital resonance
D) Hydrostatic equilibrium
|