A magnetic field induction

It can be imagined that one conductor creates the magnetic field and the other in this field acquires its action. 

Accept the direction of the probe contour normal n freely oriented in a given point of the magnetic field as a direction of the force line. The force characteristic of the magnetic field is a vector B in the direction of the normal vector n its absolute value is determined by the maximum torque acting on a contour in this point. Then, 

Vector B = Bn is referred to as a magnetic field induction vector. 

The magnetic field is schematically presented in full analogy to the electric field the B vectors at any point are parallel to the tangent to force lines and their density is proportional to the B value. 

For the description of the magnetic field we require one more characteristic—field strength H. In vacuum, the two characteristics differ only by a constant, namely, B = jUoH however inside of a body magnetic characteristics mentioned differ noticeably (refer to Section 5.4). Remember that the two characteristics appear also in the description of the electric field properties (see Section 4.2.2). 

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Figure 5.15 Movement of a charge in a plane perpendicular to a magnetic field induction.

The concept of a vector flux d through a surface dS has been given in Sections (2.8.3) and (4.1.3). Being a particular case of a more general theory of a vector field, the same concepts can be applied to a magnetic field as well. An elementary flux d of a magnetic field induction vector B through the surface dS is equal to a scalar product of B and dS... 

Magnetic flux unit—weber (Wb) (a magnetic field induction flux in 1 T through the surface of unit area)... 

Alternating-current motors are classified as induction motors or synchronous motors. Faraday found that a stationaiy wire in a magnetic field produced no current. However, when the wire continues to move across magnetic lines of force, it produces a continual current. When the motion stops, so does the current. Thus Faraday proved that electric current is only produced from relative motion between the wire and magnetic field. It is called an induced current—an electromagnetic induction effect. 

One henry is the inductance when one ampere flowing in the coil generates a magnetic field strength of one weber. 

This magnetic induction is the mechanism behind the spin-orbit interaction in the rest frame of a nucleus only a static electric field is observed, whereas an electron in relative motion will experience a magnetic field with which it can interact through its spin. 

Any NMR field-cycling (FC) relaxometry experiment presumes that the sample is subject to a magnetic field of various intensities for time intervals of varying durations. More specifically, between the various intervals of a relaxation-time measurement, the external magnetic field induction... 

The density (or flux) of the lines of force in a solid placed in a magnetic field (H) is termed the magnetic induction, B, and is given by the relationship. 

When a substance is placed in a magnetic field H, it develops a certain amount of magnetization (magnetic moment per unit volume) M given by M = yH, where y is the magnetic susceptibility. The magnetic induction B is defined as... 

In the conventional NMR experiment, a radio-frequency field is applied continuously to a sample in a magnetic field. The radio-frequency power must be kept low to avoid saturation. An NMR spectrum is obtained by sweeping the rf field through the range of Larmor frequencies of the observed nucleus. The nuclear induction current (Section 1.8.1) is amplified and recorded as a function of frequency. This method, which yields the frequency domain spectrum f(ai), is known as the steady-state absorption or continuous wave (CW) NMR spectroscopy [1-3]. 

If one of the metals (commonly referred to as superconductors) is castin the form of a ring and an external magnetic field is applied perpendicularly to its plane and then removed, a current will flow round the ring induced by-Faraday induction. This current will produce a magnetic field, proportional to the current, and the size of the current may be observed by measuring dm field. Were the ring (e g., one made of lead) at a temperature above 7.2 K, this current and field would decay to zero in a fraction of a second. 

Names and symbols used for galvanomagnetic and thermomagnetic effects in crystals are summarized in Table 15.8. In the presence of a magnetic field, crystal properties become functions of the magnetic induction B, and the ORRs, hitherto applied in the zero-field form Lik = Lki are... 

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