Search results

The magnetic field in the volume of a long, thin loop of wire, wrapped around a metallic core (solenoid) when an electric current is passed through it, ... more

The Sears–Haack body is the shape with the lowest theoretical wave drag in supersonic flow, for a given body length and given volume.The mathematical ... more

An electromagnet is a type of magnet in which the magnetic field is produced by electric current. The magnetic field disappears when the current is turned ... more

Lotka’s law, named after Alfred J. Lotka, is one of a variety of special applications of Zipf’s law. It describes the frequency of publication ... more

In geometry, the Euler line is a line determined from any triangle that is not equilateral. It passes through several important points determined from the ... more

The electric field describes the electric force experienced by a motionless positively charged test particle at any point in space relative to the ... more

In optics, the numerical aperture (NA) of an optical system is a dimensionless number that characterizes the range of angles over which the system can ... more

A uniform electric field is produced by placing a potential difference (or voltage) across two parallel metal plates. A uniform field is one in which the ... more

The general equation for a circle with a center not necessary at the pole, gives the length of the radius of the circle.
The polar coordinate system ... more

A magnetic dipole is a closed circulation of electric current. A simple example of this is a single loop of wire with some constant current through ... more