أكاديميا - كولنز - معاجم الجيب العلمية - الفيزياء - انكليزي - فرنسي - عربي الحرف ١_ s

Academia - Collins - Pocket Scientific Dictionaries - Physics - English - French - Arabic Letter 1_ S


satellite motion
Engrenage of artificial suites

Satellite movement. See orbit.


saturation
saturation f

Satisfaction. The state of the system when an operation is completed. Thus, a solution is saturated when the solvent cannot absorb any more solute. Saturated air cannot hold more vapor. It is not possible to increase the intensity of magnetization of a magnetically saturated material.
See domains.


scalar
scalaire

Selma. numerical. A measurement has size but no direction. Examples include: mass, volume, density, energy, and temperature. On the other hand, we need to mention the trend as well as the volume. To describe a vector.


scaler
Echelle f de comptage

stylus. A device whose circuitry allows the ampere meter to show the rate of change and/or transfer of energy in radiation. We can use this number instead of the counter used with the Geiger-Muller tube.


semiconductor
semiconductor m

Semiconductor. A material capable of transferring some charge, less than a metal does and more than an insulator does. See conduction, electric. The resistance of the semiconductor decreases with increasing temperature. It also decreases if the semiconductor contains certain impurities.
The most common semiconductors are silicon and germanium.

A few atoms in the crystals of these two materials lose their electrons, and these electrons move around the crystal like electrons in the electron gas of the metal. Adding small amounts of the right type of impurities provides more charge carriers.
The n-type semiconductor carries many negative electrons, while the p-type material carries the charge through positive holes. We can assume that the hole is a missing electron.
A diode is a p-n p-n junction, where a p-type material is in close contact with a p-type site. Electrons and holes flow through the junction for a short period of time, releasing a voltage that allows current to pass in only one direction.

320

Neutral atom.
Positive anion (bearing a “hole”)
Free negative electron 7

Pure silicon
n-type silicon
P type silicon

We can look at a transistor as two p-n junctions arranged back to back.
See also integrated circuit.


series circuits
Multiple circuits in the series

Circuits in series. Electrical components connected in a circuit such that there is the same current in each of them. The voltage between the ends of the group is equal to the sum of the voltages between the ends of each component. The resistance R of the set of resistors in (a) below is equal to the sum of its resistances, that is: R=R1+R2+R3.
In the case of capacitors in series, as in (b), 1/C=1/C1+1/C2+1/C3.

(a) I = current

V = V1 + V2 + V3
IR = IR1+ IR2+ IR3
R = R₁+ R2 + R3

(b) Charge = 0

V = V1 + V2 + V3
Q/C = Q/C₁ + Q/C2 + Q/C3
1/C = 1/C1 + 1/2 + 1/C3

Compare with parallel circuits.