Physics · OCR H556 · Topic 5.5

Astrophysics and cosmology

Stars, electromagnetic radiation from stars, cosmology.

  • 3 sub-topics
  • Taught in Year 13
  • 47 practice questions
  • 3 animated lessons
Practice questions (47) Lessons Worksheets coming soon All OCR Physics topics

What the specification says

Every sub-topic OCR can examine in this topic, with its reference number from the official specification. The Y12 and Y13 tags show when each sub-topic is usually taught.

  1. 5.5.1StarsY13
  2. 5.5.2Electromagnetic radiation from starsY13
  3. 5.5.3CosmologyY13

Try 2 questions

Easy and medium questions from this topic, each with a worked solutions and the mark for every step. All 47 questions in this topic, free, no account needed.

Thermodynamics

Not needed for Year 12Easy

Black body radiation · Year 13 · 3 marks

A black body is heated from 3000 K to 6000 K.
  1. (a)
    Define a black body.
    (1)
  2. (b)
    Describe two changes to its emission spectrum.
    (2)
Show worked solutionHide worked solution

Part (a)1 mark

  1. A body that absorbs all the radiation that falls on it.

Part (b)2 marks

  1. The peak moves to a shorter wavelength.
  2. The intensity at every wavelength (and the total power) increases.

Total3

  • M
  • A
  • B
How did it go?

Report a problem with this question

Space

Not needed for Year 12Medium

The Hertzsprung–Russell diagram · Year 13 · 4 marks

Stars can be plotted on an HR diagram of luminosity against temperature.
  1. (a)
    State the axes of the diagram, including the direction of the temperature axis.
    (2)
  2. (b)
    Describe where main sequence stars lie, and explain their position.
    (2)
Show worked solutionHide worked solution

Part (a)2 marks

  1. Luminosity (log scale) vertically;
  2. surface temperature horizontally, decreasing to the right.

Part (b)2 marks

  1. A diagonal band from hot and bright (top left) to cool and dim (bottom right).
  2. These stars are fusing hydrogen into helium in their cores.

Total4

  • M
  • A
  • B
How did it go?

Report a problem with this question