A galaxy is a large collection of stars and our galaxy is the Milky Way, so this Year 11 sheet opens with the star collections and their home. A star and a cloud of gas and dust appear in the answers, with nuclear fusion powering stars.
Key Takeaways
A galaxy is a large collection of stars (Q1).
Our galaxy is called the Milky Way (Q2).
Q5 records nuclear fusion as the star energy source.
Section A: Multiple Choice Questions (1 Mark Each)
Choose the correct option for each question.
1.A galaxy is a
(a) large collection of stars(b) single star(c) planet(d) moon
2.Our galaxy is called the
(a) Milky Way(b) Andromeda(c) Solar System(d) Orion
3.The Sun is
(a) a star(b) a planet(c) a moon(d) a galaxy
4.A protostar forms from
(a) a cloud of gas and dust(b) a dying planet(c) the Moon(d) another star
5.Most of the energy released by a star comes from
(a) nuclear fusion(b) burning(c) nuclear fission(d) chemical reactions
6.The main evidence that the universe is expanding is
(a) the redshift of light from distant galaxies(b) the brightness of the Sun(c) the colour of stars(d) the motion of the Moon
Section B: Short Answer Type Questions (2 Marks Each)
Show all steps clearly.
7.What is a galaxy?
8.Name our galaxy.
9.What is the Sun made of?
10.How does a star produce its energy?
11.What is a protostar?
12.What is a supernova?
13.What is redshift?
14.How does a star like the Sun end its life?
Section C: Numericals & Word Problems (3 Marks Each)
Apply the concepts to solve the problems. Show all working.
15.Light travels at 3 × 10⁸ m/s. Using distance = speed × time, find how far light travels in 1 second.
16.Light from the Sun takes 500 s to reach Earth. Using distance = speed × time with a speed of 3 × 10⁸ m/s, find the distance from Earth to the Sun.
17.Light from a star takes 4 years to reach Earth. Using 1 light year = 9.5 × 10¹⁵ m, find the distance in metres.
18.A galaxy is moving away at a speed of 2000 km/s. The Hubble constant is 70 km/s per Mpc. Using d = v ÷ H₀, find the distance of the galaxy in Mpc.
19.Light from a distant galaxy has an observed wavelength of 520 nm but was emitted at 500 nm. Using redshift z = (λobserved − λrest) ÷ λrest, find the redshift.
20.1 light year = 9.5 × 10¹⁵ m. Convert a distance of 2 light years to metres.
Answer Key
1. a) large collection of stars
2. a) Milky Way
3. a) a star
4. a) a cloud of gas and dust
5. a) nuclear fusion
6. a) the redshift of light from distant galaxies
7. Refer to solution guide.
8. Refer to solution guide.
9. Refer to solution guide.
10. Refer to solution guide.
11. Refer to solution guide.
12. Refer to solution guide.
13. Refer to solution guide.
14. Refer to solution guide.
15. Refer to solution guide.
16. Refer to solution guide.
17. Refer to solution guide.
18. Refer to solution guide.
19. Refer to solution guide.
20. Refer to solution guide.
End of Worksheet
People Also Ask
What is a galaxy?
A large collection of stars, option (a) in this worksheet (Q1).
What is our galaxy called?
The Milky Way, option (a) in this worksheet (Q2).
What powers stars?
Nuclear fusion, option (a) in this worksheet (Q5).
Stuck on a similar problem? Clear your next doubt instantly with the Doubt Solver.
Browse more free worksheets for IGCSE Year 11.