The sensation of a frequency is commonly referred to as the pitch of a sound. A high pitch sound corresponds to a high frequency sound wave and a low pitch sound corresponds to a low frequency sound wave. ... That is, two sound waves sound good when played together if one sound has twice the frequency of the other.
The correct answer is the last option. The force that moving, charged particles exert on one another is called electromagnetic force. This force involves physical interaction between two electrically charged particles. It is seen as electromagnetic fields such as electric fields, magnetic fields and light.
