PHYSICS FINAL REVIEW AYUKO NAAA

• Light


  A form of electromagnetic radiation that our eyes perceive
• Light


  • It travels in waves
  • Understanding its speed is crucial to unraveling the mysteries of the universe
• The speed of light was first accurately measured by Danish astronomer Ole Rømer

  17th century
• Speed of light


  299,792 kilometers per second (or about 186,282 miles per second) is the widely accepted speed of light in a vacuum
• Speed of light


  It is a fundamental constant in physics and astronomy, denoted by 'c' in scientific equations
• Importance of speed of light


  • It is not just a cosmic speed limit
  • It plays a crucial role in various scientific fields like Einstein's theory of relativity, space exploration, telecommunications, and more
• Light-year


  The distance light travels in one year, approximately 5.88 trillion miles
• The Universe is 13.5 Billion years old
• Wavelength


  The distance between successive peaks (or troughs) of a wave, the length of one complete wave cycle
• Frequency


  The number of wave cycles that pass a given point per unit of time, usually measured in Hertz (Hz) where one Hertz equals one cycle per second
• Wavelength and frequency


  There is an inverse relationship between them - as wavelength increases, frequency decreases, and vice versa
• Speed = Wavelength x Frequency
• The electromagnetic spectrum is a cosmic palette of energy, revealing the diverse range of electromagnetic waves that traverse the universe
• Types of waves in the electromagnetic spectrum

  • Radio waves
  • Microwaves
  • Infrared radiation
  • Visible light
  • Ultraviolet radiation
  • X-rays
  • Gamma rays
• Radio waves


  • Have the longest wavelengths and are used for communication, broadcasting, and radar
• Microwaves


  • Have shorter wavelengths than radio waves and are commonly used for cooking and in various communication technologies
• Infrared radiation


  • Also known as heat radiation, it is felt as warmth and is utilized in night vision technology, weather forecasting, and various industrial and medical applications
• Visible light


  • The only part of the spectrum that our eyes can perceive, consisting of different colors each corresponding to a specific wavelength
• Ultraviolet (UV) radiation


  • Has shorter wavelengths than visible light, is invisible to the human eye, but plays a vital role in processes like photosynthesis and is responsible for sunburn
• 1. rays


  • Have very short wavelengths and high energy, commonly used in medical imaging, airport security, and scientific research
• Gamma rays


  • Have the shortest wavelengths and the highest energy in the spectrum, produced in nuclear reactions and used in cancer treatment and sterilization processes
• Inductor


  Also called a coil, choke, or reactor. A passive two-terminal electrical component that stores energy in a magnetic field when electric current flows through it. Typically consists of an insulated wire wound into a coil.
• How does an inductor work?

  1. When current increases, they try to stop it with an opposing force

  2. When current decreases, they try to prevent it by pushing electrons to maintain movement
• Inductors


  • They don't want change, they prefer to stay the same or to do things slowly in a circuit
• Where do we use inductors?

  • Use in boost converters to increase the DC output voltage
  • Use to filter different frequencies
• Electromagnetic inductance


  A fundamental property of electrical circuits and devices governed by Faraday's law of electromagnetic induction
• Sample Problem 3


  Given: 3.5m long, 10cm diameter solenoid, 2.8 T magnetic field

  Find: Magnitude of magnetic flux through the core
• Magnetic force is caused by the motion of charges.
• Electric as well as magnetic forces exist among moving electric charges.
• The unit of the magnetic field is Tesla.
• Magnetic force


  The magnetic force between two moving charges may be described as the effect exerted upon either charge by a magnetic field created by the other.
• The magnetic field is a vector quantity.