Electromagnetic Waves

• The wavelength is the distance between two consecutive peaks or troughs.
• Radio wave, Microwave, Infrared light, Visible light, UV-ray, X-ray, and Gamma Ray
• Electric field lines are perpendicular to magnetic field lines
• Wireless communication uses radio waves
• Microwaves can be used for cooking food because they have high frequency and short wavelength which causes water molecules to vibrate rapidly causing friction and heating up the food
• Visible light has a range of colors from red to violet
• Ultraviolet rays are not visible but cause skin cancer if exposed too much
• UV rays cause sunburn and skin cancer
• UV rays can spot fake bills
• X-rays are used by doctors to see inside our bodies
• Gamma Ray - can be use to kill cancer cells, but can also cause mutations.
• Gamma rays are very dangerous as they penetrate through most materials, including human flesh.
• Infrared is heat radiation that we feel as warmth
• Gamma rays are very dangerous and can kill cells, so it's only used when necessary
• Radio waves have the longest wavelength and lowest frequency
• Radio waves are used for radio communication and TV broadcasting
• Gamma rays are emitted during nuclear reactions such as nuclear explosions and nuclear fission
• Infrared is used as heaters or remote controls
• Microwaves are used for cooking food and satellite communications
• X-rays are used for medical imaging and detecting hidden objects
• Radio waves are used for communication over large distances (e.g., radio broadcasting) and for transmitting data wirelessly between devices such as computers and smartphones.
• Red, Orange, Yellow, Blue, Indigo, Violet
• Visible light can be seen by our eyes
• Ultraviolet is used to sterilize water and kill bacteria on surfaces
• Red has the longest wavelength and has lowest frequencies.
• Gamma rays have very high energy and are dangerous to humans
• Violet has the shortest wavelength and highest frequency.
• Mechanical wave - transfer energy through a material medium.
• Electromagnetic wave - "electric" and "magnetic" fields together.
• Hans Christian Oersted - accidentally discovered that current carrying wire reflects needle of a compass.
• Hans Christian Oersted - Electricity<--> Magnetism
• Andre-Marie Ampere - works on the direction of current and various conductors.
• Michael Faraday (important) 

  - Formulated the concept of electromagnetic induction that paved way for generation of electricity.
• James Clerk Maxwell - Illustrated changing electric and link them to light.
• Heinrich Hertz - discovered the radio wave.
• Heinrich Hertz - succesfully produced electromagnetic waves and formulated equations about their properties.
• Current - flow of electrons or charges
• Voltage - supplies or powers the flow of current
• Resistance - counteracts the flow of charges
• Ohm's law - current depends with voltage