resistance (redirected from Resistance movement)

resistance, in electricity

resistance, property of an electric conductor by which it opposes a flow of electricity and dissipates electrical energy away from the circuit, usually as heat. Optimum resistance is provided by a conductor that is long, small in cross section, and of a material that conducts poorly. Resistance is basically the same for alternating and direct current circuits (see impedance). However, an alternating current of high frequency tends to travel near the surface of a conductor. Since such a current uses less of the available cross section of the conductor than a direct current, it meets with more resistance than a direct current. In circuit analysis an ideal resistor, i.e., a circuit component whose only property is resistance, is called a resistance. The phenomenon of resistance arises from the interactions of electrons with ions in the conductor. The unit of resistance is the ohm. See superconductivity; Ohm's law; conduction.

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resistance, in biology

resistance, in biology: see immunity.

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resistance, in psychiatry

resistance, in psychiatry: see psychoanalysis.

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resistance

Opposition that a material or electrical circuit offers to the flow of electric current. It is the property of a circuit that transforms electrical energy into heat energy as it opposes the flow of current. The resistance R, the electromotive force or voltage V, and the current I are related by Ohm's law. The resistance of an electrical conductor generally increases with increasing temperature and is utilized in devices such as lamps and heaters. The ohm (Ω) is the common unit of electrical resistance; one ohm is equal to one volt (see electromotive force) per ampere.

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Resistance

 or Underground

Clandestine groups opposed to Nazi rule in German-occupied Europe in World War II. The groups included civilians who worked secretly against the occupation and armed bands of partisans or guerrilla fighters. Resistance activities ranged from assisting the escape of Jews and Allied airmen shot down over enemy territory to committing sabotage, ambushing German patrols, and sending intelligence information to the Allies. Resistance groups were not always unified; in some countries, rival groups divided along communist and noncommunist lines. However, in France the clandestine National Council of the Resistance coordinated all French groups, which gave support to the Normandy Campaign and participated in the August 1944 uprising that helped liberate Paris. Resistance groups in other northern European countries also undertook military actions to help the Allied forces in 1944–45.

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resistance

1. 

a. the opposition to a flow of electric current through a circuit component, medium, or substance. It is the magnitude of the real part of the impedance and is measured in ohms.

b. (as modifier): resistance coupling

2. any force that tends to retard or oppose motion

3. (in psychoanalytical theory) the tendency of a person to prevent the translation of repressed thoughts and ideas from the unconscious to the conscious and esp to resist the analyst's attempt to bring this about

4. Physics the magnitude of the real part of the acoustic or mechanical impedance

5. See passive resistance

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resistance [ri′zis·təns]

(acoustics)

acoustic resistance

(electricity)

The opposition that a device or material offers to the flow of direct current, equal to the voltage drop across the element divided by the current through the element. Also known as electrical resistance.

In an alternating-current circuit, the real part of the complex impedance.

(fluid mechanics)

fluid resistance

(mechanics)

In damped harmonic motion, the ratio of the frictional resistive force to the speed. Also known as damping coefficient; damping constant; mechanical resistance.