Hard

• • step-down transformer decreases voltage
  • current in primary coil produces magnetic field
  • current is alternating causing a changing magnetic field in the core
  • The core strengthens the field at the secondary coil
  • Field lines interact with secondary coil which induces a voltage
  • Transformers won’t work with a direct current
• • identification of cosmic background radiation
  • CMBR appears to be the same in all directions which implies all parts of the Universe were in contact a long time ago
  • wavelength has increased as the universe was hotter long ago
  • Identification of red shift of galaxies
  • the further the galaxy is the greater the red-shift
  • larger redshift means faster movement of galaxies so the further away, the faster the galaxy moves away
  • galaxies moving apart from each other implies expansion from a single point or since the Big Bang