Chapter 12 · 5 hours

Universe

SEE past exam questions

Past questions and answers

35 questions set from this chapter, 5 of them more than once; 4 are most repeated (set, or a close variant set, in 3 or more exams). Most repeated first.

Most repeated · 3 of 31 exams
Asked 3 times
2082 Chaitra · Gandaki · 2 marks
SEE 2080 model question, Set 3, Science and Technology · 1 mark
2081 Chaitra · Gandaki · 2 marks
2081 Chaitra · Lumbini · 2 marks

Write any two differences between open and closed universe.

Answer

Closed universe	Open universe
Average density of the universe is greater than the critical density.	Average density is less than the critical density.
Gravity is strong enough to stop the expansion; the universe finally contracts (Big Crunch).	Gravity is too weak to stop the expansion; the universe expands forever.

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Most repeated · 3 of 31 exams
Asked 3 times
2082 Chaitra · Koshi · 2 marks
2080 Chaitra · Lumbini · 2 marks
2080 Chaitra · Madhesh · 2 marks

How does the conclusion of Hubbles study support Big Bang theory? Mention any two points.

Answer

Hubble found that distant galaxies show redshift and that their speed of moving away is directly proportional to their distance ( $v = Hd$ ).

Galaxies are moving away from one another, so the universe is expanding. Going backwards in time, all matter must have been together at a single point, which then exploded (Big Bang).
Since all galaxies are moving apart in every direction, with the farthest moving fastest, it shows they were thrown out from one common point in a huge explosion about 13.8 billion years ago.

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Most repeated · 3 of 31 exams
Asked 2 times
2082 Asar · Grade increment · 1 mark
SEE 2080 model question, Set 2, Science and Technology · 1 mark
2081 Chaitra · Karnali · 1 mark

Under which condition can a flat universe be hypothesized?
(a) When the average density is greater than the critical density. (b) When the average density is equal to critical density. (c) When the average density is less than the critical density. (d) When the average density and critical density are not comparable.

Similar questions: Condition for closed universe MCQ (2081 Chaitra · Madhesh)

Answer

(b) When the average density is equal to critical density.

In a flat universe gravity is just enough to slow the expansion down to zero only after infinite time, which happens when average density equals the critical density.

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Most repeated · 3 of 31 exams
2081 Chaitra · Madhesh · 1 mark

Under what condition can close-universe be hypothesized? (a) When average density is greater than the critical density. (b) When average density is less than the critical density. (c) When average density and critical density are equal. (d) When average density and critical density are not comparable.

Similar questions: Condition for flat universe (2082 Asar · Grade increment)

Answer

(a) When average density is greater than the critical density.

The gravity is then strong enough to stop the expansion and pull everything back, so the universe is closed.

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Asked 2 times
2081 Shrawan · Grade increment · 1 mark
SEE 2080 model question, Set 2, Science and Technology · 1 mark
2081 Chaitra · Sudurpashchim · 1 mark

Due to which force heavenly bodies in the universe remain in their own position?
(a) gravity (b) gravitational force (c) magnetic force (d) nuclear force

Answer

(b) gravitational force.

The mutual gravitational attraction between heavenly bodies keeps them in their orbits and positions (planets around the Sun, moons around planets).

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Asked 2 times
2080 Chaitra · Sudurpashchim · 2 marks
2080 Chaitra · Karnali · 2 marks

"Role of gravitational force is very important for the birth and death of a star." Justify the statement.

Answer

Birth: A star is born in a nebula (a cloud of hydrogen gas and dust). Gravitational force pulls the gas inward and the cloud contracts. As it contracts, pressure and temperature rise until nuclear fusion of hydrogen begins and a star is formed.

Life and death: During the star's life, the inward pull of gravity is balanced by the outward pressure of fusion energy. When the fuel is used up, the outward pressure falls and gravity makes the core collapse. Depending on its mass, the star becomes a white dwarf, a neutron star or a black hole (after a supernova for massive stars).

So gravitational force is essential both for the birth and the death of a star.

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2081 Chaitra · Koshi · 1 mark
SEE 2080 model question, Set 3, Science and Technology · 1 mark

What is the value of H in Hubble's law, v = Hd ? (a) 65 km/s/Mpc (b) 68 km/s/Mpc (c) 70 km/s/Mpc (d) 73 km/s/Mpc

Answer

(c) 70 km/s/Mpc.

The accepted approximate value of Hubble's constant is about 70 km/s per megaparsec; a galaxy 1 Mpc away recedes at about 70 km/s.

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2080 Chaitra · Bagmati · 2 marks

Study the graph of hypothesis about future of universe given aside. What does R curve represent? In which respect P is different from R?
Figure: Graph of radius of the universe (y-axis) against time since the Big Bang (x-axis). Three curves start from the origin: the top curve (P) keeps rising steeply and continues upward (accelerating expansion); a middle curve rises and levels off gradually; the lowest curve (R) rises, reaches a maximum, then falls back to zero (collapse). Curve labels P and R are marked at points on the curves.

Answer

R curve: It represents a closed universe. The radius of the universe increases up to a maximum, then decreases and falls to zero, i.e. the universe expands first, then contracts and ends in a Big Crunch.

Difference of P from R: P represents an open universe, in which the radius keeps increasing forever (the universe expands endlessly, average density less than critical density). In R, the expansion stops and reverses because the average density is greater than the critical density.

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2080 Grade increment · 1 mark

'Galaxies are moving away from each other' which principle is concerned with this statement?

Answer

This statement is concerned with Hubble's law (the expanding universe principle, supporting the Big Bang theory).

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2080 Grade increment · 2 marks

Explain the theory of origin of universe based on the figure shown.
Figure: Dark photograph of a star field with a bright cluster of galaxies/stars spread out from a central point, suggesting an expanding universe (Big Bang / expanding universe).

Answer

The figure shows matter spread outward from a central point, which represents the Big Bang theory.

According to this theory, about 13.8 billion years ago all matter and energy of the universe were concentrated at a single point of infinite density and temperature.
A huge explosion (Big Bang) occurred and matter was thrown out in all directions. As it expanded and cooled, it formed galaxies, stars and planets.
The galaxies are still moving away from each other, so the universe is still expanding, as confirmed by Hubble's law and redshift.

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2080 Chaitra · Gandaki · 2 marks

How does the conclusion of Hubble's study support Big Bang theory? Mention any one point. Which logic related to future of universe is proved by Hubble's law?

Answer

Point: Hubble found that all galaxies are moving away from one another, with farther galaxies moving faster. So the universe is expanding, and in the past all matter was at one point that exploded, as the Big Bang theory states.

Logic about the future: Hubble's law proves that the universe is expanding. Whether the expansion will continue forever (open universe) or later stop and reverse (closed universe) depends on the average density of the universe compared with the critical density, which is the main factor that decides the future of the universe.

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2080 Chaitra · Karnali · 1 mark

How can we say that the universe is expanding?

Answer

We can say so because the light from distant galaxies shows redshift, and by Hubble's law the galaxies are moving away from us with speed proportional to their distance. This shows that the universe is expanding.

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2080 Chaitra · Koshi · 2 marks

A figure of balloon is given alongside.
(i) How will you demonstrate Big Bang theory by using it?
(ii) How does the demonstration also support the conclusion of Hubble's study?
Figure: Photograph of a deflated/partly inflated balloon with small marks (dots) on its surface.

Answer

(i) Demonstration: Mark small dots on a balloon to represent galaxies. Initially the balloon is small and the dots are close together (the universe at the beginning). When the balloon is inflated (the Big Bang and expansion), the dots move away from one another in all directions, just as galaxies move apart as the universe expands.

(ii) Support to Hubble's conclusion: As the balloon inflates, a dot that is farther from a chosen dot moves away faster than a nearer one. Similarly, Hubble concluded that farther galaxies recede faster ( $v \propto d$ ), and all move away from each other, so the universe is expanding.

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2080 Chaitra · Sudurpashchim · 1 mark

What is the weight of a body having mass 100 kg on the moon?
(a) 2500 N (b) 1000 N (c) 980 N (d) 167 N

Answer

(d) 167 N.

Given: $m = 100$ kg, $g_{moon} = 1.67$ m/s $^2$ .

$W = mg = 100 \times 1.67 = 167$ N.

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2080 Chaitra · Sudurpashchim · 4 marks

The acceleration due to gravity of three heavenly bodies are given in the table.

Heavenly bodies Acceleration due to gravity
A 9.8 m/s $^2$
B 25 m/s $^2$
C 1.67 m/s $^2$
(i) Calculate the velocity of object falling freely towards the surface of B in 5th second.
(ii) If a man can lift 50 kg mass on the surface of the earth, how much mass can he lift on the surface of C?
(iii) Why are there big craters on the surface of heavenly body of C?
(iv) Although the mass of Jupiter is 319 times of the mass of the earth, but its acceleration due to gravity does not increase in the same ratio, why?
Figure: Table of acceleration due to gravity: A 9.8, B 25, C 1.67 m/s^2.

Heavenly bodies	Acceleration due to gravity
A	9.8 m/s $^2$
B	25 m/s $^2$
C	1.67 m/s $^2$

Answer

(i) Given: $g = 25$ m/s $^2$ (body B), $u = 0$ (freely falling from rest).

Velocity after 5 s (at the end of the 5th second):

$v = u + gt = 0 + 25 \times 5 = 125 \text{ m/s}$

So the velocity is 125 m/s (it was 100 m/s at the start of the 5th second).

(ii) The force he can lift on Earth is $F = mg = 50 \times 9.8 = 490$ N. On C the same force can lift

$m = \frac{F}{g_C} = \frac{490}{1.67} \approx 293.4 \text{ kg}$

He can lift about 293 kg on C.

(iii) C (with $g = 1.67$ m/s $^2$ , like the Moon) has no atmosphere. Meteoroids falling on it are not burnt by friction and are not slowed down, so they strike the surface at high speed and make big craters. There is also no weathering or erosion to erase them.

(iv) $g = \dfrac{GM}{R^2}$ depends on the mass and also on the square of the radius. Jupiter is much larger in radius (about 11.2 times that of Earth), so although its mass is 319 times greater, $g$ increases by only about $319/11.2^2 \approx 2.5$ times.

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2081 Chaitra · Bagmati · 2 marks

Differentiate between the flat universe and closed universe in two points.

Answer

Flat universe	Closed universe
Average density is equal to the critical density ( $\rho = \rho_c$ ).	Average density is greater than the critical density ( $\rho > \rho_c$ ).
It expands forever. The expansion slows down with time, but the expansion rate only approaches zero as time tends to infinity; the universe does not stop expanding or stay at a constant size.	Gravity eventually stops the expansion, and then the universe contracts, ending in a Big Crunch.

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2081 Shrawan · Grade increment · 2 marks

Write the type of the universe based on the given condition
i. some velocity retains, if the gravity on a body becomes zero
ii. if the gravity and the velocity of the celestial bodies becomes zero at the same time.

Answer

i. Open universe. If gravity becomes zero (too weak) the bodies still retain some velocity, so they keep moving apart and the universe expands forever.

ii. Flat universe. When gravity and the velocity of the celestial bodies both become zero at the same time, the expansion just stops, which is the case in a flat universe (average density equal to critical density).

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2081 Chaitra · Karnali · 1 mark

Why is Big-Bang theory considered the most reliable theory among all the theories related to the origin of universe?

Answer

Because it is supported by scientific evidence: the observed expansion of the universe (Hubble's law and redshift of galaxies) and the cosmic microwave background radiation, which other theories cannot explain.

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2081 Chaitra · Koshi · 1 mark

Write the definition of flat universe.

Answer

A flat universe is one whose spatial geometry has zero curvature (Euclidean geometry); equivalently, its total density parameter is $\Omega_{\text{total}}=1$ , i.e. its average total density equals the critical density.

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2081 Chaitra · Madhesh · 1 mark

According to Hubble's law, on what factor does the speed of star depend?

Answer

According to Hubble's law, the speed (recessional velocity) of a star or galaxy depends on its distance from us; it is directly proportional to the distance ( $v = Hd$ ).

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2081 Chaitra · Sudurpashchim · 1 mark

Write one condition required for a closed universe.
Figure: Only the Nepali text is legible in the scan (the English line is cut off at the page edge).

Answer

The average density of the universe must be greater than the critical density (so gravity is strong enough to stop the expansion and make the universe contract).

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2082 Chaitra · Bagmati · 2 marks

Study the graph related to the future of the universe. (a) According to line Z, how will the universe end? (b) According to which line does the universe remain constant?
Figure: Graph: y-axis 'Radius of the universe', x-axis 'Time since the Big bang'. Three curves from the origin: X rises steeply and keeps increasing; Y rises and levels off to a constant (flat) value; Z rises, peaks, then falls back down toward the axis.

Answer

(a) Line Z shows a closed universe. The universe expands to a maximum radius, then contracts and collapses to a point, ending in a Big Crunch.

(b) The universe remains constant (at a fixed radius) according to line Y, the flat universe, where the average density equals the critical density.

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2082 Asar · Grade increment · 1 mark

Write the conclusion of Hubble's study.

Answer

Hubble concluded that galaxies are moving away from each other and the farther a galaxy is, the faster it moves away; hence the universe is expanding.

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2082 Chaitra · Karnali · 2 marks

The graph shows the relation between velocity and distance of celestial bodies. Write the equation related to this graph. To which study is graph related?
Figure: Scatter graph with a straight line rising from the origin: x-axis Distance (mpc) marked 100, 200, 300, 400; y-axis Recessional velocity (km/s) marked 1000, 2000, 3000; points scattered close to the line.

Answer

Equation: $v = Hd$ , where $v$ is the recessional velocity of a galaxy, $d$ its distance from the observer and $H$ Hubble's constant (the slope of the line).

Study: The graph is related to Hubble's study (Hubble's law) of the expanding universe.

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2082 Chaitra · Koshi · 4 marks

Why is it not possible to land safely on the Moon using a parachute?

Answer

A parachute works only in the presence of air. It opens and slows the fall because the air resists its motion (air resistance, or drag, acts upward on the large area of the canopy).

The Moon has no atmosphere (almost vacuum), so there is no air to push on the parachute and no air resistance.
The parachute therefore cannot open or slow the lander; the craft keeps accelerating under the Moon's gravity ( $g \approx 1.67$ m/s $^2$ ) and would hit the surface at high speed and be damaged.
So a safe landing on the Moon needs retro rockets (thrusters that fire against the direction of motion) to reduce the speed, rather than a parachute.

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2082 Chaitra · Lumbini · 1 mark

In the given graph of future of the universe, what type of universe does 'B' represent?
Figure: Graph of radius of the universe (vertical axis) against time since the Big Bang (horizontal axis) with three curves: A keeps rising steeply, B rises and levels off to a constant radius, C rises then falls back down.

Answer

Curve B represents a flat universe. Its radius increases and then levels off to a constant value, because the average density is equal to the critical density.

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2082 Chaitra · Madhesh · 2 marks

What is the future of the universe in which Earth is present; open, closed or flat? Explain with suitable argument.

Answer

The universe in which Earth is present is an open universe.

Observations show that galaxies are receding and the expansion is continuing, even accelerating. The visible matter in the universe gives an average density that is less than the critical density.
Gravity is therefore too weak to stop the expansion, so the universe will keep expanding forever.

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2082 Chaitra · Sudurpashchim · 2 marks

An astronomer studies two galaxies, P and Q which are very far from each other, and finds that galaxy P is at greater distance from the Earth compared to the galaxy Q. Based on these information, answer the following questions.
(a) Which galaxy has a greater recessional velocity? (b) Why are P and Q going away from each other?

Answer

(a) Galaxy P has the greater recessional velocity. By Hubble's law $v = Hd$ , speed is proportional to distance, and P is farther from the Earth.

(b) P and Q are going away from each other because the universe is expanding as a result of the Big Bang; the space between galaxies is stretching, so all galaxies move apart.

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2079 Chaitra · Sudurpashchim · 2 marks

Differentiate between planets and stars in any two points.

Answer

Planets	Stars
They do not have their own light; they shine by reflecting sunlight	They have their own light and heat
They revolve around a star (the Sun)	They do not revolve around planets; they are the centres of planetary systems

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2079 Chaitra · Gandaki · 4 marks

In a science laboratory of a school, a chart shows the following data.

Planet Diameter (km) Temperature Gases in atmosphere
A 12035.2 $478^\circ$ C CO $_2$ , H $_2$ O, O $_2$
B 12672 $-18^\circ$ C N $_2$ , O $_2$ , CO $_2$ , H $_2$ O
C 6742.4 $-35^\circ$ C CO $_2$ , N $_2$ , Ar, O $_2$
D 1139040 $-140^\circ$ C H $_2$ , He, CH $_4$
(a) Write the name of the planet 'A'. (b) Why does planet 'A' have a high temperature? (c) In your opinion, which planet is suitable for the survival of living beings on it? Write any two reasons.

Planet	Diameter (km)	Temperature	Gases in atmosphere
A	12035.2	$478^\circ$ C	CO $_2$ , H $_2$ O, O $_2$
B	12672	$-18^\circ$ C	N $_2$ , O $_2$ , CO $_2$ , H $_2$ O
C	6742.4	$-35^\circ$ C	CO $_2$ , N $_2$ , Ar, O $_2$
D	1139040	$-140^\circ$ C	H $_2$ , He, CH $_4$

Answer

(a) Planet A is Venus.

(b) Venus has a very thick atmosphere of carbon dioxide. The CO $_2$ traps the heat of the Sun (a strong greenhouse effect), so it is the hottest planet.

(c) Planet B (the Earth-like planet) is suitable for life because:

Its atmosphere contains oxygen and nitrogen, which living beings need for respiration (and growth).
It contains water vapour (water), and its temperature is moderate compared with the other planets, so life can survive.

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CDC model paper 2080, Science and Technology · 1 mark

Which is the most realistic theory about origin of the universe? (a) Heliocentric theory (b) Geocentric theory (c) Newton's theory (d) Big Bang theory

Answer

(d) Big Bang theory.

It is supported by observations such as the expansion of the universe (Hubble's law) and the cosmic microwave background, so it is the most accepted theory of the origin of the universe.

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CDC model paper 2080, Science and Technology · 1 mark

What is the main cause of determination of future of universe?

Answer

The future of the universe is determined by the average density of matter in the universe compared with the critical density (that is, by the strength of gravitational force due to the total matter). Greater density gives a closed universe, equal density a flat universe, and lower density an open universe.

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SEE 2080 model question, Set 1, Science and Technology · 1 mark

Which of the following is proved by Hubble's law?
(a) Universe is contracting. (b) Universe is expanding. (c) Universe remains same. (d) Galaxies appeared to be closer.

Answer

(b) Universe is expanding.

Hubble's law, $v = Hd$ , shows that galaxies recede faster the farther they are, which means the universe is expanding.

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SEE 2080 model question, Set 1, Science and Technology · 1 mark

What is meant by redshift?

Answer

Redshift is the shifting of the spectral lines of light from a distant galaxy towards the red (longer wavelength) end of the spectrum, which happens when the source is moving away from the observer.

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Questions from SEE 2082 Science and Technology, 1041 Koshi (Board exam, Chaitra 2082 (scanned PDF, bilingual)), SEE 2082 Science and Technology, 1041 Madhesh (Board exam, Chaitra 2082 (scanned PDF, bilingual)), SEE 2082 Science and Technology, 1041 Bagmati (Board exam, Chaitra 2082 (scanned PDF, bilingual)), SEE 2082 Science and Technology, 1041 Gandaki (Board exam, Chaitra 2082 (scanned PDF, bilingual)), SEE 2082 Science and Technology, 1041 Lumbini (Board exam, Chaitra 2082 (scanned PDF, bilingual)), SEE 2082 Science and Technology, 1041 Karnali (Board exam, Chaitra 2082 (scanned PDF, bilingual)), SEE 2082 Science and Technology, 1041 Sudurpashchim (Board exam, Chaitra 2082 (scanned PDF, bilingual)), SEE 2081 Science and Technology, 1041 Koshi (Board exam, Chaitra 2081 (PDF; official answer keys exist on the bidhyamandir page)), SEE 2081 Science and Technology, 1041 Madhesh (Board exam, Chaitra 2081 (PDF; official answer keys exist on the bidhyamandir page)), SEE 2081 Science and Technology, 1041 Bagmati (Board exam, Chaitra 2081 (PDF; official answer keys exist on the bidhyamandir page)), SEE 2081 Science and Technology, 1041 Gandaki (Board exam, Chaitra 2081 (PDF; official answer keys exist on the bidhyamandir page)), SEE 2081 Science and Technology, 1041 Lumbini (Board exam, Chaitra 2081 (PDF; official answer keys exist on the bidhyamandir page)), SEE 2081 Science and Technology, 1041 Karnali (Board exam, Chaitra 2081 (PDF; official answer keys exist on the bidhyamandir page)), SEE 2081 Science and Technology, 1041 Sudurpashchim (Board exam, Chaitra 2081 (PDF; official answer keys exist on the bidhyamandir page)), SEE 2080 Science and Technology, 1041 Koshi (Board exam, 2080 (scanned PDF, bilingual)), SEE 2080 Science and Technology, 1041 Madhesh (Board exam, 2080 (scanned PDF, bilingual)), SEE 2080 Science and Technology, 1041 Bagmati (Board exam, 2080 (scanned PDF, bilingual)), SEE 2080 Science and Technology, 1041 Gandaki (Board exam, 2080 (scanned PDF, bilingual)), SEE 2080 Science and Technology, 1041 Lumbini (Board exam, 2080 (scanned PDF, bilingual)), SEE 2080 Science and Technology, 1041 Karnali (Board exam, 2080 (scanned PDF, bilingual)), SEE 2080 Science and Technology, 1041 Sudurpashchim (Board exam, 2080 (scanned PDF, bilingual)), SEE 2082 Science and Technology, GI-1041 (grade increment) (Grade increment, Asar 2083 (PDF)), SEE 2081 Science and Technology, GI-1041 (grade increment) (Grade increment 2081 (8 page images); month taken from the August 2025 post, check), SEE 2080 Science and Technology, GI-1041 (grade increment) (Grade increment 2080 (PDF)), CDC model paper 2080, Science and Technology (with answer key) (Official CDC model paper, pages 2-9; answer key pages 10-15), SEE 2080 model question, Set 1, Science and Technology (Model paper Set 1 (typed PDF, publisher not named, no answers)), SEE 2080 model question, Set 2, Science and Technology (Model paper Set 2 (typed PDF, publisher not named, no answers)), SEE 2080 model question, Set 3, Science and Technology (Model paper Set 3 (typed PDF, publisher not named, no answers)), SEE 2079 Compulsory Science (RE-111) Koshi (Board exam, Chaitra 2079 (2023), last year of the old course (scanned PDF, bilingual, 75 marks); only questions that fit the current outline were taken), SEE 2079 Compulsory Science (RE-111) Madhesh (Board exam, Chaitra 2079 (2023), last year of the old course (scanned PDF, bilingual, 75 marks); only questions that fit the current outline were taken), SEE 2079 Compulsory Science (RE-111) Bagmati (Board exam, Chaitra 2079 (2023), last year of the old course (scanned PDF, bilingual, 75 marks); only questions that fit the current outline were taken), SEE 2079 Compulsory Science (RE-111) Gandaki (Board exam, Chaitra 2079 (2023), last year of the old course (scanned PDF, bilingual, 75 marks); only questions that fit the current outline were taken), SEE 2079 Compulsory Science (RE-111) Lumbini (Board exam, Chaitra 2079 (2023), last year of the old course (scanned PDF, bilingual, 75 marks); only questions that fit the current outline were taken), SEE 2079 Compulsory Science (RE-111) Karnali (Board exam, Chaitra 2079 (2023), last year of the old course (scanned PDF, bilingual, 75 marks); only questions that fit the current outline were taken) and SEE 2079 Compulsory Science (RE-111) Sudurpashchim (Board exam, Chaitra 2079 (2023), last year of the old course (scanned PDF, bilingual, 75 marks); only questions that fit the current outline were taken). Answers are written for this site; check them against your class notes.

Chapter titles and hours from the official syllabus ↗

Past questions and answers

1.Write any two differences between open and closed universe.

2.How does the conclusion of Hubbles study support Big Bang theory? Mention any two points.

5.Due to which force heavenly bodies in the universe remain in their own position? (a) gravity (b) gravitational force (c) magnetic force (d) nuclear force

6."Role of gravitational force is very important for the birth and death of a star." Justify the statement.

7.What is the value of H in Hubble's law, v = Hd ? (a) 65 km/s/Mpc (b) 68 km/s/Mpc (c) 70 km/s/Mpc (d) 73 km/s/Mpc

9.'Galaxies are moving away from each other' which principle is concerned with this statement?

10.Explain the theory of origin of universe based on the figure shown. Figure: Dark photograph of a star field with a bright cluster of galaxies/stars spread out from a central point, suggesting an expanding universe (Big Bang / expanding universe).

11.How does the conclusion of Hubble's study support Big Bang theory? Mention any one point. Which logic related to future of universe is proved by Hubble's law?

12.How can we say that the universe is expanding?

13.A figure of balloon is given alongside. (i) How will you demonstrate Big Bang theory by using it? (ii) How does the demonstration also support the conclusion of Hubble's study? Figure: Photograph of a deflated/partly inflated balloon with small marks (dots) on its surface.

14.What is the weight of a body having mass 100 kg on the moon? (a) 2500 N (b) 1000 N (c) 980 N (d) 167 N

16.Differentiate between the flat universe and closed universe in two points.

17.Write the type of the universe based on the given condition i. some velocity retains, if the gravity on a body becomes zero ii. if the gravity and the velocity of the celestial bodies becomes zero at the same time.

18.Why is Big-Bang theory considered the most reliable theory among all the theories related to the origin of universe?

19.Write the definition of flat universe.

20.According to Hubble's law, on what factor does the speed of star depend?

21.Write one condition required for a closed universe. Figure: Only the Nepali text is legible in the scan (the English line is cut off at the page edge).

23.Write the conclusion of Hubble's study.

25.Why is it not possible to land safely on the Moon using a parachute?

26.Which theory is closely related to Hubble's study? (a) Heliocentric theory (b) Geocentric theory (c) Big-bang theory (d) Hubble's theory

28.What is the future of the universe in which Earth is present; open, closed or flat? Explain with suitable argument.

30.Differentiate between planets and stars in any two points.

32.Which is the most realistic theory about origin of the universe? (a) Heliocentric theory (b) Geocentric theory (c) Newton's theory (d) Big Bang theory

33.What is the main cause of determination of future of universe?

34.Which of the following is proved by Hubble's law? (a) Universe is contracting. (b) Universe is expanding. (c) Universe remains same. (d) Galaxies appeared to be closer.

35.What is meant by redshift?

Write any two differences between open and closed universe.

How does the conclusion of Hubbles study support Big Bang theory? Mention any two points.

Due to which force heavenly bodies in the universe remain in their own position?
(a) gravity (b) gravitational force (c) magnetic force (d) nuclear force

"Role of gravitational force is very important for the birth and death of a star." Justify the statement.

What is the value of H in Hubble's law, v = Hd ? (a) 65 km/s/Mpc (b) 68 km/s/Mpc (c) 70 km/s/Mpc (d) 73 km/s/Mpc

'Galaxies are moving away from each other' which principle is concerned with this statement?

Explain the theory of origin of universe based on the figure shown.
Figure: Dark photograph of a star field with a bright cluster of galaxies/stars spread out from a central point, suggesting an expanding universe (Big Bang / expanding universe).

How does the conclusion of Hubble's study support Big Bang theory? Mention any one point. Which logic related to future of universe is proved by Hubble's law?

How can we say that the universe is expanding?

A figure of balloon is given alongside.
(i) How will you demonstrate Big Bang theory by using it?
(ii) How does the demonstration also support the conclusion of Hubble's study?
Figure: Photograph of a deflated/partly inflated balloon with small marks (dots) on its surface.

What is the weight of a body having mass 100 kg on the moon?
(a) 2500 N (b) 1000 N (c) 980 N (d) 167 N

Differentiate between the flat universe and closed universe in two points.

Write the type of the universe based on the given condition
i. some velocity retains, if the gravity on a body becomes zero
ii. if the gravity and the velocity of the celestial bodies becomes zero at the same time.

Why is Big-Bang theory considered the most reliable theory among all the theories related to the origin of universe?

Write the definition of flat universe.

According to Hubble's law, on what factor does the speed of star depend?

Write one condition required for a closed universe.
Figure: Only the Nepali text is legible in the scan (the English line is cut off at the page edge).

Write the conclusion of Hubble's study.

Why is it not possible to land safely on the Moon using a parachute?

Which theory is closely related to Hubble's study?
(a) Heliocentric theory (b) Geocentric theory (c) Big-bang theory (d) Hubble's theory

What is the future of the universe in which Earth is present; open, closed or flat? Explain with suitable argument.

Differentiate between planets and stars in any two points.

Which is the most realistic theory about origin of the universe? (a) Heliocentric theory (b) Geocentric theory (c) Newton's theory (d) Big Bang theory

What is the main cause of determination of future of universe?

Which of the following is proved by Hubble's law?
(a) Universe is contracting. (b) Universe is expanding. (c) Universe remains same. (d) Galaxies appeared to be closer.

What is meant by redshift?