Doppler effect, redshift and the expanding universe

Doppler effect, redshift and the expanding universe Quiz

Spec 161–163 · Edexcel A-Level Physics: Quiz

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5 questions, one answer each

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  1. 1. A source emitting sound of constant frequency moves away from a stationary observer. How does the observed frequency compare with the emitted frequency?

    • A. It is higher
    • B. It is lower
    • C. It is the same
    • D. It alternates

  2. 2. A galaxy has redshift z = 0.020. What is its recession speed? (c = 3.00 × 10⁸ m s⁻¹)

    • A. 6.0×1066.0 \times 10^{6} m s⁻¹
    • B. 1.5×10101.5 \times 10^{10} m s⁻¹
    • C. 6.0×1056.0 \times 10^{5} m s⁻¹
    • D. 2.0×1062.0 \times 10^{6} m s⁻¹

  3. 3. Which statement about the Hubble law v = H₀d is correct?

    • A. Nearer galaxies recede faster
    • B. All galaxies recede at the same speed
    • C. Galaxy speed is proportional to distance
    • D. Only galaxies in one direction recede

  4. 4. H₀ = 2.2 × 10⁻¹⁸ s⁻¹. What is 1/H₀, the estimated age of the universe, in seconds?

    • A. 2.2×10−182.2 \times 10^{-18} s
    • B. 6.6×1066.6 \times 10^{6} s
    • C. 4.5×10174.5 \times 10^{17} s
    • D. 1.4×10101.4 \times 10^{10} s

  5. 5. Why is the fate of the universe uncertain?

    • A. Light travels too fast to measure
    • B. Galaxies are all moving at the speed of light
    • C. The total mass, including dark matter, is not known
    • D. The Doppler effect does not apply to light

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