Read the text and decide whether the statement is true(T) of false(F).
Magnetic
Field
A magnetic field is a mathematical
description of the magnetic influence of electric currents and magnetic
materials. The magnetic field at any given point is specified by both a
direction and a magnitude (or strength); as such it is a vector field.
The magnetic field is most commonly
defined in terms of the Lorentz force it exerts on moving electric charges.
There are two separate but closely related fields to which the name 'magnetic
field' can refer: a magnetic B field and a magnetic H field.
Magnetic fields are produced by
moving electric charges and the intrinsic magnetic moments of elementary
particles associated with a fundamental quantum property, their spin. In
special relativity, electric and magnetic fields are two interrelated aspects
of a single object, called the electromagnetic field tensor; the aspect of the electromagnetic
field that is seen as a magnetic field is dependent on the reference frame of
the observer. In quantum physics, the electromagnetic field is quantized and electromagnetic
interactions result from the exchange of photons.
Magnetic
fields have had many uses in ancient and modern society. The Earth produces its
own magnetic field, which is important in navigation. Rotating magnetic fields
are utilized in both electric motors and generators. Magnetic forces give information
about the charge carriers in a material through the Hall effect. The interaction
of magnetic fields in electric devices such as transformers is studied in the discipline
of magnetic circuits.1. The
magnetic field at any given point is specified by two characteristics.