EM waves

• EM waves can be described as transverse waves with oscillating electric and magnetic fields that travel through space at the speed of light.
• The electric field is strongest at right angles to the direction of propagation, while the magnetic field is strongest along the direction of propagation.
• Electric field lines are perpendicular to the magnetic field lines.
• The wavelength is the distance between two consecutive peaks or troughs, while the frequency is the number of complete cycles per second.
• Magnetic field lines are also perpendicular to both the electric field lines and the direction of wave propagation.
• Electric field lines are always perpendicular to the direction of wave propagation.
• An electromagnetic wave consists of both electric and magnetic fields that oscillate perpendicularly to each other and to the direction of energy transfer.
• Frequency (f) is defined as the number of complete cycles or wavelengths passing a given point per second.
• Wavelength (λ) is defined as the distance between two consecutive points on an electromagnetic wave that have the same phase difference.
• Amplitude (A) is defined as the maximum displacement from equilibrium position of any particle in the medium due to the passage of an electromagnetic wave.
• Wave velocity (v) = wave frequency (f) x wavelength (λ)
• Wavefronts are lines of constant phase difference between two points on an electromagnetic wave.
• In free space, electromagnetic waves travel at the speed of light (c).
• Radio waves have the longest wavelength and lowest frequency, making them ideal for long-distance communication over large areas.
• Wave speed (v) can be calculated using the formula v = fλ, where f is the frequency and λ is the wavelength.
• Speed (v) is defined as the rate at which the wave travels through space.
• EM waves travel through space as transverse waves with no need for any medium.
• There are different types of waves according to the direction of vibration and direction of motion of a wave.
• Surface waves are a type of wave that is formed by the surface of the water.
• The five wave parameters are: frequency, wavelength, amplitude, speed, and direction.
• Mechanical waves are waves that are not capable of transmitting their energy through a vacuum and require a medium to transport their energy from one location to another.
• Electromagnetic waves are waves that are capable of transmitting their energy through a vacuum (i.e., empty space) and are placed in an electromagnetic spectrum in order of decreasing wavelength and increasing frequency.
• Radio waves, micro waves, infrared, visible light, ultraviolet radiation, x-rays and gamma rays are the seven EM waves.
• A pregnant woman went to a lab and asked for an X-ray examination but the technician did not allow her to have an X-ray examination due to the risk of harm to the fetus.
• Earthquake is an example of a mechanical wave and being located in the Pacific ring of fire, we experience frequent earthquakes more than other countries.
• It is important to learn the do's and don'ts before, during and after an earthquake.
• Mechanical waves need a medium to propagate and cannot travel in outer space.
• Electromagnetic waves do not need a medium to propagate and can travel in vacuum (outer space).
• The relationship between energy and frequency are directly proportional and inversely proportional to wavelength.