Properties of electromagnetic waves

• Electromagnetic waves are transverse waves that consist of electric and magnetic fields that oscillate at 90° to each other.
• Electromagnetic waves transfer energy from one place to another, for example, electromagnetic waves from the Sun transport thermal and light energy through space (vacuum) to the Earth.
• Electromagnetic waves can travel through a vacuum and do not require any medium to travel from one point to another.
• The speed of electromagnetic waves in vacuum is 3.0 x 108 m/s.
• Electromagnetic waves slow down when travelling through water or glass.
• Electromagnetic waves obey the wave equation, v = fA.
• Electromagnetic waves obey the laws of reflection and refraction.
• Electromagnetic waves carry no electric charge as they are neither positively nor negatively charged.
• The frequencies of electromagnetic waves do not change when they travel from one medium to another, for example, from water to glass.
• The frequency of an electromagnetic wave f depends only on the source of the wave.
• The speeds and wavelengths of electromagnetic waves change from one medium to another.
• Only repulsion between a specimen and a charged object is a sure test that allows us to conclude that the specimen is charged (not neutral).
• The specimen should have a similar charge as the charged object.
• Only repulsion between a specimen and a charged object is a sure test that allows us to conclude that the specimen is charged (not neutral).
• The specimen should have a similar charge as the charged object.