câu hỏi  |
câu trả lời |
What is the difference between resistance and reactance? What are 2 kinds of reactance? bắt đầu học
|
|
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).
|
|
|
|
bắt đầu học
|
|
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? bắt đầu học
|
|
It can change in magnitude (amplitude), frequency, and phase.
|
|
|
What does Inductive reactance cause? bắt đầu học
|
|
It causes the current to lag behind the voltage.
|
|
|
What does capacitive reactance cause? bắt đầu học
|
|
It causes the current to lead the voltage.
|
|
|
Where is reactance observed: AC circuits or DC circuits? bắt đầu học
|
|
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? bắt đầu học
|
|
Resistance limits the amount of current that flows for a given voltage.
|
|
|
Give the definitions of an electrical and an electronic circuit. bắt đầu học
|
|
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? bắt đầu học
|
|
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. bắt đầu học
|
|
Active: Transistors, operational amplifiers, batteries. Passive: Resistors, capacitors, inductors, diodes.
|
|
|
What types of circuits can you name? bắt đầu học
|
|
Series circuits, parallel circuits, and series-parallel (combination) circuits.
|
|
|
What is the difference between series and parallel circuits? bắt đầu học
|
|
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? bắt đầu học
|
|
Open circuits (break in the path), short circuits (unintended low-resistance path), and component failure.
|
|
|
