Life Cycle of Stars — Homi Bhabha Class 9 Physics MCQs with Solutions
Free Homi Bhabha Class 9 Physics Life Cycle of Stars MCQs with step-by-step solutions (10 questions). Part of Observing Space / Astronomy. Practise online on Prepizo — no login needed.
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Questions with solutions
Q1 — Life Cycle of Stars · medium · theory
Stars are born from huge clouds of gas and dust called:
A. craters
B. comets
C. asteroids
D. nebulae ✓ Correct
Solution: A star forms when a nebula (cloud of gas and dust) contracts under gravity.
Q2 — Life Cycle of Stars · hard · theory
Stars, including the Sun, produce their enormous energy by:
A. chemical reactions
B. burning coal
C. nuclear fusion of hydrogen into helium ✓ Correct
D. nuclear fission of uranium
Solution: In the core, hydrogen nuclei fuse into helium, releasing vast energy (nuclear fusion).
Q3 — Life Cycle of Stars · medium · theory
The main fuel that powers the Sun at present is:
A. oxygen
B. carbon
C. helium
D. hydrogen ✓ Correct
Solution: The Sun mainly fuses hydrogen into helium in its core.
Q4 — Life Cycle of Stars · hard · theory
A medium-sized star like the Sun will, near the end of its life, first swell into a:
A. white dwarf directly
B. neutron star
C. black hole
D. red giant ✓ Correct
Solution: A Sun-like star expands into a red giant, then sheds its outer layers to leave a white dwarf.
Q5 — Life Cycle of Stars · hard · theory
A very massive star ends its life in a huge explosion called a:
A. meteor shower
B. nebula
C. solar eclipse
D. supernova ✓ Correct
Solution: Massive stars explode as supernovae, leaving behind a neutron star or a black hole.
Q6 — Life Cycle of Stars · medium · theory
The final remnant of a low-mass star like the Sun, after it has exhausted its fuel, is a:
A. red giant
B. black hole
C. supernova
D. white dwarf ✓ Correct
Solution: After the red giant stage, a Sun-like star leaves a small, dense, hot white dwarf.
Q7 — Life Cycle of Stars · easy · theory
Stars are born inside vast clouds of gas and dust in space. Such a cloud is called a:
A. Meteor
B. Nebula ✓ Correct
C. Comet
D. Crater
Solution: A nebula is a cloud of gas (mostly hydrogen) and dust. Under gravity, dense regions of a nebula collapse and heat up until nuclear fusion begins, giving birth to a new star.
Q8 — Life Cycle of Stars · medium · theory
During most of its lifetime (the main-sequence stage), a star shines by:
A. Nuclear fusion of hydrogen into helium in its core ✓ Correct
B. Reflecting light received from other stars
C. Burning wood and coal like a fire
D. Chemical reactions on its cool surface
Solution: On the main sequence, the crushing pressure and temperature in the core fuse hydrogen nuclei into helium, releasing enormous energy. This balances gravity and keeps the star stable for a long time.
Q9 — Life Cycle of Stars · medium · theory
Whether a star finally ends up as a quiet white dwarf, or instead explodes as a supernova leaving a neutron star or black hole, depends mainly on the star s:
A. Name given by astronomers
B. Colour only
C. Mass ✓ Correct
D. Distance from Earth
Solution: Mass decides a star s fate. Low-mass stars like the Sun end as white dwarfs, while much more massive stars collapse and explode as supernovae, leaving behind neutron stars or black holes.
Q10 — Life Cycle of Stars · hard · theory
A very massive star contains far more hydrogen fuel than the Sun, yet it lives a much shorter life. The best explanation is that:
A. A massive star burns its fuel enormously faster because its core is hotter and under greater pressure ✓ Correct
B. A massive star does not use nuclear fusion at all
C. Bigger stars are simply much farther away from us
D. A massive star actually has less fuel than the Sun
Solution: Greater mass means a hotter, denser core and a far higher fusion rate. The star consumes its huge fuel supply so rapidly that its total lifetime is much shorter than that of a smaller star like the Sun.