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Date November 2016 Marks available 2 Reference code 16N.3.SL.TZ0.17
Level Standard level Paper Paper 3 Time zone Time zone 0
Command term Identify Question number 17 Adapted from N/A

Question

The peak wavelength of the cosmic microwave background (CMB) radiation spectrum corresponds to a temperature of 2.76 K.

Identify two other characteristics of the CMB radiation that are predicted from the Hot Big Bang theory.

[2]
a.

A spectral line in the hydrogen spectrum measured in the laboratory today has a wavelength of 21cm. Since the emission of the CMB radiation, the cosmic scale factor has changed by a factor of 1100. Determine the wavelength of the 21cm spectral line in the CMB radiation when it is observed today.

[1]
b.

Markscheme

isotropic/appears the same from every viewing angle

homogenous/same throughout the universe

black-body radiation

a.

23 100 «cm»
OR
231 «m»

b.

Examiners report

[N/A]
a.
[N/A]
b.

Syllabus sections

Option D: Astrophysics » Option D: Astrophysics (Core topics) » D.3 – Cosmology
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