What does resistance mean? After reading the article, you will know the answer

In physics, resistance is a very important concept. It refers to the resistance encountered when current passes through a conductor. The magnitude of resistance is expressed in ohms (Ω), and its value depends on factors such as the material, length, cross-sectional area, and temperature of the surrounding environment of the conductor. This article will provide you with a detailed introduction to the definition, function, and calculation of resistance

1、 Definition of Resistance

Resistance refers to the resistance encountered by current passing through a conductor. When there is current passing through a conductor, the charge will move inside the conductor, and this process will be accompanied by energy loss. This energy loss is generated by the interaction between electrons and atoms inside the conductor. Therefore, resistance is actually the resistance generated by the interaction between electrons and atoms inside a conductor

2、 The function of resistance

1. Protect the circuit

Resistors play a protective role in electronic circuits. For example, when we use devices such as mobile phones and computers, if the voltage is too high, it may cause damage to the equipment. At this point, the resistor will act as a current limiter, preventing excessive current and protecting the normal operation of the equipment

2. Heating element

In some household appliances, such as electric stoves, electric kettles, and other heating elements, resistance wires are used as heating elements. When current passes through a resistance wire, the wire will generate heat, thereby producing heat. This principle is called Joule's law

3. Damper

In some mechanical equipment, such as shock absorbers for cars and compressors for air conditioners, resistors are used as dampers. When mechanical equipment moves, it generates vibration and noise. At this point, the resistor will act as a damper, reducing vibration and noise

4. Voltage divider

In some circuits, voltage distribution is required. At this point, one or more resistors can be used to form a voltage divider, which divides the high voltage to different ports according to a pre-set proportional relationship

3、 How to calculate resistance

The formula for calculating resistance is: R=V/I, where R represents the resistance value, V represents the voltage, and I represents the current. It should be noted that this formula is only applicable to pure resistance circuits. For complex circuits containing capacitors or inductors, more sophisticated methods are required for calculation