Коллоквиум 1 часть 3

What is the difference between resistance and reactance? What are 2 kinds of reactance?

Resistance opposes both AC and DC and dissipates energy as heat. Reactance opposes only AC and stores and releases energy. The two kinds are Inductive Reactance (X_L) and Capacitive Reactance (X_C).

What is impedance?

Impedance (Z) is the total opposition a circuit offers to alternating current. It is a complex quantity combining both resistance (R) and reactance (X).

What are three ways current can change in a circuit?

It can change in magnitude (amplitude), frequency, and phase.

What does Inductive reactance cause?

It causes the current to lag behind the voltage.

What does capacitive reactance cause?

It causes the current to lead the voltage.

Where is reactance observed: AC circuits or DC circuits?

Reactance is observed only in AC circuits. In a steady DC circuit, inductors act as short circuits and capacitors as open circuits.

How does resistance affect the current?

Resistance limits the amount of current that flows for a given voltage.

Give the definitions of an electrical and an electronic circuit.

An electrical circuit is a path for transmitting electric current, often for power distribution and conversion. An electronic circuit uses components to control the flow of electrons for processing information.

What circuit elements are called active? What circuit elements are called passive?

Active elements can inject power into a circuit (e.g., transistors, ICs). Passive elements cannot and can only absorb or store energy (e.g., resistors, capacitors, inductors).

Give the examples of active and passive elements.

Active: Transistors, operational amplifiers, batteries. Passive: Resistors, capacitors, inductors, diodes.

What types of circuits can you name?

Series circuits, parallel circuits, and series-parallel (combination) circuits.

What is the difference between series and parallel circuits?

In a series circuit, components are connected end-to-end, so the same current flows through all of them. In a parallel circuit, components are connected across common points, so the same voltage is applied to all of them.

What are the main troubles in circuits?

Open circuits (break in the path), short circuits (unintended low-resistance path), and component failure.