Prúd

Prúd is a Slovak term that denotes flow or current. In physics, it refers to the rate at which something moves through a region or across a boundary. The concept appears in electrical contexts as elektrický prúd and in fluid dynamics as prúd tekutiny, where it describes both the amount of material moving per unit time and the direction of movement. The conventional direction of current is the direction of positive charge movement.

Elektrický prúd is the rate of flow of electric charges through a conductor. It is measured in amperes (A) and represents the amount of charge that passes a point per unit time. There are direct current (DC), where the current direction is constant, and alternating current (AC), where the direction reverses periodically. Ohm's law relates current to voltage and resistance: I = V/R. Electrical power in a circuit can be expressed as P = VI, or equivalently P = I^2R.

Generation and safety are important aspects of electrical prúd. Currents arise from voltage sources such as batteries, generators, or power grids, and are managed by conductors, resistors, and other circuit elements. High currents can cause overheating, electric shocks, or fires, so insulation, fuses, and circuit breakers are used to maintain safety in electrical systems.

Prúd in fluids describes the volumetric flow rate, the volume of fluid passing a cross-section per unit time. Its common units are cubic meters per second (m^3/s) or liters per second (L/s); mass flow rate is measured in kilograms per second (kg/s). In incompressible flow, the continuity equation A v = constant expresses how speed and cross-sectional area adjust to conserve volume as fluid moves through a conduit.