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

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


machine
machine f

Machine . A device that, if a certain force is applied to it at one point, produces an output force at another place. Simple examples of this include: levers, pulleys, and hydraulic machines.

In most cases, the output power, or the oppressive “load,” is greater than the input power, or the applied “effort.” The mechanical advantage is greater than one. This benefit is balanced by the need for the input power to move farther than the output, and the velocity ratios are greater than one. Energy is also transferred to the resulting friction, and here the efficiency is always less than one.

Simple hydraulic press


magnet
aimant m

Magnet. An object with domains aligned in one direction. Thus, it has two poles and a magnetic field around it. Magnets and electromagnets (which can be connected and disconnected) are used in many electrical machines.

The “law of magnetic force” describes how each pole is affected by the other: like poles repel each other and opposite poles attract.

The compass uses a small magnet
To show the effect of Earth's magnetism. The box is flat, and the user turns it until the ends of the needle point north and south on the compass card. Then it is easier to find other directions. For the compass's north pole to point north, the Earth behaves as if there were a south pole in the geographic north region.

magnetic field
Champ m magnetic

Magnetic field. A region of space that has a magnetic force. These fields are three-dimensional, but we show the sections in most drawings. Drawings use “lines of force” or “field lines” to show the direction of the field and its strength (the approximation of the lines) at each point. The line of force is not real, and we define it as the path followed by a free north pole (if such a pole exists).

The following drawings show sections of some simple fields.

U magnet(b)

Bar magnet (A)

Straight current A (d)

identical poles (c)

File with current (e)

Harmonic field (and)

See also earth's magnetism.


magnetic material
The material is magnetic

Magnetic material. A substance that experiences a force when it is in a magnetic field. Iron, cobalt, and nickel are some of the materials that can be strongly magnetized and are called ferromagnetic materials. Stronger magnets can be made from iron oxides called ferrites. Magnets made of materials that are difficult to magnetize but remain magnetized are called permanent magnets, and they are sometimes said to be made of hard magnetic materials. As for materials that are easy to magnetize and that are easy to demagnetize, they are called temporary magnets (made of soft materials such as soft iron!). Permanent magnets are used in loudspeakers, compasses, etc., while temporary magnets are used in transformers and magnets.
Electrical...etc.


magnification
aimantation f

Enlarge the amount the image is larger than the actual object. Magnification is often defined as the image height (the distance from the axis divided by the height
the body. When the optical system is single-lens or mirror, it is:

Zoom = image height / object height
= Image distance / Object distance

The distances of the image and the object are measured from
Pole. See ray diagrams.