vastusarvoa

Vastusarvoa is a Finnish term used in electronics to describe the resistance value of an electrical component or circuit. The term combines vastus (resistance) and arvo (value). In English, the concept is known as resistance value and is measured in ohms (symbol Ω). The resistance value is a key parameter in Ohm's law, V = I·R, and determines how much current flows for a given voltage in a circuit.

Resistance values are specified for components such as fixed resistors, variable resistors (potentiometers and trimmers), thermistors, and shunts. They may be given as nominal values with tolerances that indicate manufacturing variation, for example ±1%, ±5%. Temperature coefficient (TCR) indicates how the resistance changes with temperature, expressed in parts per million per degree Celsius (ppm/°C).

Common ranges include ohms to megaohms, with preferred-series values following standard component series (e.g., 1%, E-series). In practice, measurement of vastusarvoa is performed with a multimeter in ohms mode when the component is unpowered and isolated from circuits.

In circuit design, the vastusarvoa influences current, voltage drops, and power dissipation. It also affects impedance, particularly in AC circuits when combined with reactance. For sensors and calibrations, precise or temperature-stable values are important, and selections are made according to tolerance and TCR requirements.

See also: Ohm, Ohm's law, resistor, tolerance, temperature coefficient, multimeter.