→ Коллоквиум 1 Часть 5 → Bắt đầu học / Tải xuống MP3 Flashcards

câu hỏi		câu trả lời
What type of resistor is called a rheostat? bắt đầu học		A two-terminal variable resistor is called a rheostat.
What is a rheostat used for? bắt đầu học		It is used to control the current in a circuit.
How does a rheostat vary the value of current? bắt đầu học		By sliding a contact along a resistive element, it changes the effective length (and thus resistance) in the circuit.
What does it consist of? bắt đầu học		It consists of a coil of resistive wire and a sliding contact (wiper).
What is the function of the switch? bắt đầu học		A switch is used to open or close a circuit, thereby controlling the flow of current.
What is a resistor used for? bắt đầu học		A resistor is used to limit current, divide voltages, and adjust signal levels.
When does the temperature of a resistor rise? bắt đầu học		Its temperature rises when electrical power is dissipated as heat (P = I²R).
How are resistors rated? bắt đầu học		They are rated by their resistance value (Ohms), power rating (Watts), and tolerance (%).
What is the difference between a fixed resistor and a variable resistor? bắt đầu học		A fixed resistor has a single, unchangeable resistance value. A variable resistor (like a potentiometer or rheostat) allows its resistance to be adjusted.

Коллоквиум 1 часть 5