MDCAT Physics MCQ #325

Why do spectral lines from hydrogen in stars appear shifted to longer wavelengths?

MDCAT Physics MCQ #325

  1. Question 1

    Q1. Why do spectral lines from hydrogen in stars appear shifted to longer wavelengths?

    • A) Stars are moving away from Earth (redshift).
    • B) Interstellar absorption of short wavelengths.
    • C) Earth's atmosphere absorbs UV radiation.
    • D) Stellar temperature filters spectral output.

    Answer: Stars are moving away from Earth (redshift).

    Explanation: Cosmic expansion causes Doppler redshift. Option B creates absorption lines, not wavelength shifts.