Edexcel A Level Physics
Edexcel A Level Physics Topic 10: Space Exam Questions
Free Edexcel A Level Physics exam questions for Topic 10: Space, with a mark scheme for every pack. Covers trigonometric parallax, standard candles, luminosity and intensity, the Hertzsprung-Russell diagram, stellar evolution, redshift and Hubble's law.
Topic 10: Space exam questions
2 question packs of real past exam questions, each with its mark scheme. Do not stop after a few: answer as many as you can without notes, then mark every answer with the mark scheme. The more questions you do, the more quickly you will spot how examiners ask about each idea.
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A-Level Physics Flashcards for 2027 Onwards
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About Edexcel A Level Physics Topic 10: Space
Topic 10: Space in Edexcel A Level Physics covers astronomical distances and stars, then the Doppler effect, redshift and Hubble's law. You measure distances with trigonometric parallax and standard candles, use I = L/4πd^2, and apply the Stefan-Boltzmann and Wien laws from Topic 9 to stars. You also interpret the Hertzsprung-Russell diagram and stellar life cycles, then use z = Δλ/λ ≈ v/c and v = H0d to discuss the expanding universe, its age and dark matter. It is assessed in Paper 2: Advanced Physics II. Examiners often combine several equations to find a star's radius or distance.
What you need to know
- Parallax Trigonometric parallax uses the apparent shift of a nearby star against distant stars as the Earth orbits the Sun. A parsec is the distance at which 1 AU subtends 1 arcsecond; d (pc) = 1/p (arcsec).
- Standard candles Objects of known luminosity, such as Cepheid variables or type Ia supernovae, allow distance to be found from intensity I = L/4πd^2.
- Stellar properties L = σAT^4 and λmaxT = 2.898 × 10^-3 m K are used to find temperature, luminosity and radius of stars.
- H-R diagram and life cycles The H-R diagram plots luminosity against surface temperature (decreasing to the right). Know the main sequence, red giants, white dwarfs and the life cycles of low and high mass stars.
- Doppler and redshift z = Δλ/λ ≈ Δf/f ≈ v/c for v much less than c. Light from distant galaxies is redshifted.
- Hubble's law and cosmology v = H0d; the age of the universe is roughly 1/H0. Uncertainty in H0 and the role of dark matter affect predictions about the ultimate fate of the universe.
Common mistakes in Topic 10: Space
- Plotting temperature increasing to the right on the H-R diagram. Temperature increases to the left.
- Using d instead of d^2 in the inverse square law for intensity.
- Forgetting to convert H0 from km s^-1 Mpc^-1 into s^-1 before finding the age of the universe.
- Saying parallax works for all stars. It is only accurate for relatively nearby stars because the angles become too small to measure.
- Using z ≈ v/c for galaxies receding at a large fraction of c, where it is not valid.
Try three Topic 10: Space exam-style questions
1. A star has a parallax angle of 0.20 arcseconds. Calculate its distance in metres. 1 pc = 3.09 × 10^16 m. (2 marks)
Show the mark scheme answer
d = 1/0.20 = 5.0 pc; d = 5.0 × 3.09 × 10^16 = 1.5 × 10^17 m.
2. Taking H0 = 70 km s^-1 Mpc^-1 and 1 Mpc = 3.09 × 10^22 m, estimate the age of the universe in years. (3 marks)
Show the mark scheme answer
H0 = 70 × 10^3/3.09 × 10^22 = 2.27 × 10^-18 s^-1; age = 1/H0 = 4.4 × 10^17 s; = 4.4 × 10^17/3.15 × 10^7 = 1.4 × 10^10 years.
3. Describe the evolution of a star with a mass similar to the Sun after it leaves the main sequence. (3 marks)
Show the mark scheme answer
Hydrogen in the core runs out and the core contracts while outer layers expand and cool to form a red giant; helium fusion occurs in the core; outer layers are lost as a planetary nebula, leaving a white dwarf that cools.
Topic 10: Space FAQs
What does Edexcel A Level Physics Topic 10: Space cover?
It covers parallax, standard candles, luminosity and intensity, stellar temperatures and radii, the H-R diagram, stellar life cycles, redshift, Hubble's law and the fate of the universe.
Which paper is Topic 10: Space examined in?
It is assessed in Paper 2: Advanced Physics II, and like every topic it can also appear in Paper 3: General and Practical Principles in Physics.
What equations do I need for Space?
Learn I = L/4πd^2, L = σAT^4, λmaxT = 2.898 × 10^-3 m K, z = Δλ/λ ≈ v/c and v = H0d, and how to convert parsecs and H0 units.
