ESS
Grade-9
Easy
Question
The ______ and ___________balance and keep a main sequence star in equilibrium.
- Gravity and friction
- Gravity and air quality
- Gravity and radiation pressure
- None of these
Hint:
In the main sequence the star remains constant in size despite the outward energy flow.
The correct answer is: Gravity and radiation pressure
- In the Main Sequence Phase of a star's evolution, radiation pressure pushing outward exactly balances the gravitational pressure pulling inward (this balance is called Hydrostatic Equilibrium).
- Because these two forces are exactly in balance, the star is stable (this means it neither shrinks nor expands).
Related Questions to study
ESS
Select the model that allows a scientist to predict the exact positions of the planets in the night sky over many years.
Select the model that allows a scientist to predict the exact positions of the planets in the night sky over many years.
ESSGrade-9
ESS
The correct order of outer planets is _________.
The correct order of outer planets is _________.
ESSGrade-9
ESS
Select the correct life cycle to death for a large mass star.
Select the correct life cycle to death for a large mass star.
ESSGrade-9
ESS
The planets move in their respective orbit by_________.
The planets move in their respective orbit by_________.
ESSGrade-9
ESS
What happens when a white dwarf cools completely?
What happens when a white dwarf cools completely?
ESSGrade-9
ESS
What is the name of the planet A in the picture shown below?
What is the name of the planet A in the picture shown below?
ESSGrade-9
ESS
The sixth stage in the life cycle of a star is_____________.
The sixth stage in the life cycle of a star is_____________.
ESSGrade-9
ESS
Which of the following star shines with a blue-white color?
Which of the following star shines with a blue-white color?
ESSGrade-9
ESS
Select the INCORRECT statement.
Select the INCORRECT statement.
ESSGrade-9
ESS
All stars starts as a____________.
All stars starts as a____________.
ESSGrade-9
ESS
What is A, B, C in the image given below?
What is A, B, C in the image given below?
ESSGrade-9
ESS
What is Light Year?
What is Light Year?
ESSGrade-9
ESS
Red shift is________.
Red shift is________.
ESSGrade-9
ESS
Blackhole called "black" because___________.
Blackhole called "black" because___________.
ESSGrade-9
ESS
What elements does the Sun perfectly burns and make in the course of nuclear fusion?
What elements does the Sun perfectly burns and make in the course of nuclear fusion?
ESSGrade-9
