juhtivushindamised

Juhtivushindamised, also known as electrical impedance, is a measure of the opposition that a circuit presents to a current when a voltage is applied. It is a complex quantity that combines the effects of resistance, capacitance, and inductance in an electrical circuit. Impedance is represented by the symbol Z and is measured in ohms (Ω).

The concept of impedance is fundamental in the analysis of alternating current (AC) circuits, where the voltage and current are not in phase. In such circuits, the impedance is a function of frequency, and it can be expressed as a complex number with both real and imaginary parts. The real part of the impedance corresponds to the resistance, while the imaginary part represents the reactance, which is the opposition to the flow of current due to capacitance and inductance.

Impedance is calculated using the formula Z = V/I, where V is the voltage across the circuit and I is the current flowing through it. In a purely resistive circuit, the impedance is equal to the resistance. However, in circuits containing capacitors or inductors, the impedance varies with frequency. For a capacitor, the impedance decreases with increasing frequency, while for an inductor, it increases with frequency.

Understanding impedance is crucial for designing and analyzing electrical circuits, especially those involving AC signals. It allows engineers to predict how a circuit will respond to different frequencies and to design filters, amplifiers, and other electronic devices.