Multiple choice

Cosmic noise is caused by

  1. lighting discharges

  2. solar eruptions

  3. distant stars

  4. industrial discharges

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Cosmic noise, also called cosmic background radiation, is electromagnetic radiation from distant stars and galaxies that reaches Earth. Option A refers to lightning, option B to solar flares (solar noise), and option D is man-made industrial noise.