Growth factors are organized into three categories. Some bacteria (e.g. E. coli) do not require any growth factors: they can synthesize all essential purines, pyrimidines, amino acids and vitamins, starting with their carbon source, as part of their own intermediary metabolism.
The inductor is a conductor, usually a coil of wire, that stores energy in a magnetic field in response to the current through it. When the current changes, the magnetic field does too, inducing a voltage between the ends of the conductor.The induced voltage is proportional to the time rate of change of the current.he electric potential at any point is defined as the energy required to bring a unit test charge from an infinite distance slowly to that point. It is usually measured in volts, and one volt is the potential for which one joule of work must be expended to bring a charge of one coulomb from infinity.
As Ampere suggested, a magnetic field is produced whenever an electrical charge is in motion. The spinning and orbiting of the nucleus of an atom produces a magnetic field as does electrical current flowing through a wire. The direction of the spin and orbit determine the direction of the magnetic field. The strength of this field is called the magnetic moment. The motion of an electric charge producing a magnetic field is an essential concept in understanding magnetism. The magnetic moment of an atom can be the result of the electron's spin, which is the electron orbital motion and a change in the orbital motion of the electrons caused by an applied magnetic field.