أكاديميا - كولنز - معاجم الجيب العلمية - الفيزياء - انكليزي - فرنسي - عربي الحرف ٣_ m

Academia - Collins - Pocket Scientific Dictionaries - Physics - English - French - Arabic Letter 3_ M


meniscus
Menisque m

Crescent surface. The rising or falling edges of a liquid surface
Due to adhesion, which is the effect of surface tension.

metals
métaux mpl

Minerals Metals. A substance whose atoms have lost one or more electrons. These free particles move randomly throughout the material. They behave like gas particles. In fact, we often use the term “electron gas.”

Positive kernel
Free electron

Freely charged electrons give the metal good thermal and electrical transfer properties. See conduction. It is also the reason why the metal surfaces are smooth.

The insulator has very few free charges. The semiconductor has more free charges, and the number increases with increasing temperature.


meteorology
metrology f

meteorology. The branch of physics in which one studies climate and weather patterns and attempts to explain, predict, and change them.


meter
mètre m

Scale. Measuring device Hence a dynamometer measures force, and a thermometer measures temperature
The ammeter measures current. Electricity meters fall into two main categories. In both cases, the needle moves at an angle related to the current in the coil. In a meter moving coil, the coil itself moves. See effect motor.

In a moving-iron meter, the current passing through the coil magnetizes two pieces of “soft” iron, causing one to reject the other, and the moving iron fixed at the tip of the needle moves.

The standard meter is a milliampere meter capable of measuring very small currents. We can turn this meter around to operate with larger currents by placing a weak resistance in parallel with it. To make a voltmeter, a high resistance connected in series with it is added to the first meter. More complex arrangements allow the measurement of resistance (ohm meter), power (watt meter), and energy (joule meter).

Note that the ampere meter must be installed in series with the relevant element, while the ampere meter must be connected in parallel. Thus, in the circuit shown below, we can measure V/I and obtain a value for the resistance R.


method of mixture
Method of use

Mixture method. A technique that allows one to measure properties of matter such as specific heat capacity.

This technique involves mixing samples of different temperatures and finding the equilibrium temperature. There must be no transfer of energy to or from the outside.


microphone
microphone m

Microphone. A device that converts incoming sound waves into a variable electrical current. We may amplify the current and pass it to a vibration detector, a recording machine, or a loudspeaker. And it looks like
A moving coil microphone is a loudspeaker, but in the opposite way.

For a diagram of a simple carbon microphone, see telephone.

microscope
microscope m

microscope. An optical instrument used to give a large image of a small object. A simple microscope is a single telephoto lens. (See magnifying lens). Compound microscopes have two or more lenses. The lens closest to the body is called an object lens, while the one closest to the eye is called an eye lens.