For cyclical processes, such as rotation, oscillations, or waves, frequency is defined as a number of cycles per unit time. In physics and engineering disciplines, such as optics, acoustics, and radio, frequency is usually denoted by a Latin letter f or by the Greek letter or Î½ (nu) (see e.g. Planck's formula).
An inductor, also called a coil or reactor, is a passive two-terminal electrical component that stores electrical energy in a magnetic field when electric current is flowing through it. An inductor typically consists of an electric conductor, such as a wire, that is wound into a coil. When the current flowing through an inductor changes, the time-varying magnetic field induces a voltage in the conductor, described by Faraday's law of induction. According to Lenz's law, the direction of induced electromotive force (e.m.f.) opposes the change in current that created it.
The cylinder and pump are used to create a vacuum to help the penis become erect; the band or constriction ring is used to help maintain the erection. How Do Vacuum Constriction Devices Work? To use a vacuum constriction device: Place the pump, which can be pumped by hand or run on batteries, over the penis. Pump the air out of the cylinder so that a vacuum is created. The vacuum draws blood into the shaft of the penis and causes it to swell and become erect.