Voolutugevusest

Voolutugevusest is the Estonian term for the magnitude of electric current in a conductor, commonly referred to as current strength or current intensity. In physics, the electric current, denoted I, is the rate at which electric charge passes a cross-section of a conductor. It is measured in amperes (A). The instantaneous current I(t) can vary with time and direction, while the average current over a period is the total charge that passes divided by the time interval, Iavg = ΔQ/Δt.

In a conductor with uniform cross-section A, the current density J is the current per unit area, J = I/A, with units of amperes per square meter (A/m^2). The current density in many materials is related to the electric field by J = σE, where σ is the electrical conductivity of the material. The resistance of a uniform conductor is R = ρL/A, where ρ is resistivity and L is length, and the current is given by Ohm’s law in its common form I = V/R for a simple circuit.

Currents can be direct (DC), constant in time, or alternating (AC), periodically changing direction. For AC, the root-mean-square (RMS) value is often used for power calculations. Measurement of current is typically done with an ammeter placed in series, or with a clamp meter that measures magnetic fields generated by the current without breaking the circuit; RMS readings are standard for AC.

Voolutugevusest is fundamental to the design and analysis of electrical circuits, power transmission, and electronic devices, reflecting how much charge flows through a conductor in a given time.