General Science/Everyday Science MCQs
Topic Notes: General Science/Everyday Science
MCQs and preparation resources for competitive exams, covering important concepts, past papers, and detailed explanations.
Plato
- Biography: Ancient Greek philosopher (427–347 BCE), student of Socrates and teacher of Aristotle, founder of the Academy in Athens.
- Important Ideas:
- Theory of Forms
- Philosopher-King
- Ideal State
11
What is the event horizon?
Answer:
Point around black hole where nothing escapes
The event horizon is the theoretical boundary surrounding a black hole. Once anything passes this 'point of no return,' the gravitational pull is so great that escape is impossible even at the speed of light.
12
Red giants are
Answer:
Large, old stars
Red giants are stars in a late stage of stellar evolution. When a star exhausts the hydrogen in its core, it begins fusing hydrogen in a shell, causing the star to expand significantly and cool, giving it a reddish color.
13
Which is the most abundant element in the universe?
Answer:
Hydrogen
Hydrogen is the most abundant chemical element in the universe, making up roughly 75% of all normal matter. It was the first element created after the Big Bang and serves as the primary fuel for stars.
14
What force keeps galaxies together?
Answer:
Gravitational
Gravity is the fundamental force that holds galaxies together. It binds stars, gas, dust, and dark matter into the massive structures we observe throughout the universe.
15
A constellation is
Answer:
A group of stars forming a pattern
A constellation is an area on the celestial sphere in which a group of visible stars forms a perceived outline or pattern. There are 88 officially recognized constellations representing various figures.
16
Pulsars are
Answer:
Rotating neutron stars
Pulsars are highly magnetized, rapidly rotating neutron stars that emit beams of electromagnetic radiation. As they rotate, these beams sweep across Earth, appearing as regular pulses of radiation.
17
Quasars are
Answer:
Energetic cores of distant galaxies
Quasars are the extremely bright and active centers of distant galaxies, powered by supermassive black holes actively consuming matter and releasing enormous energy across the electromagnetic spectrum.
18
What do we call the collection of billions of stars held by gravity?
Answer:
Galaxy
A galaxy is a massive, gravitationally bound system that consists of stars, stellar remnants, an interstellar medium of gas and dust, and dark matter. The Milky Way is our home galaxy.
19
The lifecycle of a star ends as a
Answer:
White dwarf, neutron star, or black hole
Depending on its initial mass, a star will end its life as a white dwarf (low mass), a neutron star (massive stars), or a black hole (most massive stars) after exhausting its nuclear fuel.
20
Stars are mostly made of
Answer:
Hydrogen and helium
Stars are massive spheres of plasma held together by gravity. They are primarily composed of hydrogen (about 70%) and helium (about 28%). The fusion of hydrogen into helium in the core provides the energy stars emit.