Definition of Conduction – In physics or more specifically in the field of electricity, the term conduction is one of the words that is heard quite often. In general, conduction can be understood as a process of heat energy transmission. Conduction can also be interpreted as a process that we unconsciously always find in everyday life.
For example, when a person is walking barefoot on asphalt that is hot enough, the conduction process from the asphalt to the feet will automatically occur. This will make the person’s feet feel hot like asphalt.
Well, in this article, we will discuss in depth the meaning of conduction. Not only that, it will also be discussed about the type of conduction, the characteristics of conduction, to various examples of conduction that we can find in our daily activities.
A. Definition of Conduction
The concept of conduction is a process of heat transfer that occurs in a substance without being accompanied by the transfer of some particles from the substance. Conduction itself usually occurs in solids, especially solids that have the properties of conductors. A conductor is known to be an object capable of transmitting heat, electric current, and even sound.
In the concept of conduction, the transfer of this heat can be affected by several things, starting from the type of object, the cross-sectional area of the conducting substance, to the difference in temperature at the end of each object. Not only that, the length of the intermediate substance that heat is used to propagate can also affect the transfer
In addition to conduction, heat can also transfer in two other ways, namely convection and radiation. Convection or flow is the process of heat transfer through a flow in which the medium moves. When a particle or substance moves and causes heat to propagate, it can be confirmed that convection will occur.
Convection usually occurs in liquids and gases such as air or wind. For example, like the movement of water up and down when heated. Cold water will automatically go down, while hot water will easily move up.
Then, radiation or radiation is the transfer of heat or heat without an intermediate substance. Radiation itself can generally move accompanied by light or through the form of electromagnetic wave propagation.
Some examples of heat transfer without intermediate substances are, for example, radiation or heat from the sun to the earth through a vacuum. This process is unconsciously very useful for everyday human activities, such as drying clothes. Not only for humans, radiation also has an influence on the process of plant photosynthesis, there are land and sea winds, and so on.
B. Types of Conduction
After knowing the meaning of conduction, here are some types of conduction that you should know, among others:
1. Tunak Conduction
The first type of conduction is passive conduction. This type of conduction can be understood as a stable condition where there is no heat absorption or emission at any cross section. The left and right side of the face will both maintain their respective temperatures. This will ultimately result in a constant temperature gradient throughout the plate because the amount of heat that flows is the same in each section.
2. Temporary Conduction
The second type of conduction is transient conduction. In this temporary conduction, the temperature can change at certain objects and times. This mode depends on the temperature to be the main point. Temporary conduction itself usually occurs when there is a known temperature change on the outside or inside the object.
3. Electrical Conduction
The third type of conduction is electrical conduction. Electrical conduction can be understood as an event that occurs when there is an electric current passing through it. Electrical conduction itself is very dependent on the physical structure to how an electron is bound to the material.
4. Voice Conduction
The fourth type of conduction is voice conduction. Sound conduction is one type of conduction capable of producing a vibration at the same time causing various atoms to vibrate through matter. It’s just that, in sound conduction there are isolators whose individual atoms don’t vibrate easily, which are like sonic isolators. This will basically make sound conduction function as a sound dampener.
C. Conduction Characteristics
Conduction as we know ourselves is a transfer of heat through a solid substance that does not experience displacement. In the conduction itself there are several characteristics that can be used to distinguish it from the other two types.
Well, here are some conduction characteristics that you need to pay attention to, including:
- Requires intermediate substances (medium)
- Must be in contact.
- Occurs in solids.
- Heat transfer is not followed by intermediate substances.
In heat transfer by conduction, a formula can be used to calculate, among others as follows:
Q/t = H = k (Δt)/l
H = Heat speed that propagates per unit time (J/s)
K = thermal conductivity of the material (W/mK)
A = Cross-sectional area (m2)
Δt = temperature change (T2 – T1) (K)
L = length of the conveyor (m)
D. Examples of Conduction
After understanding the meaning of conduction as well as the difference with other types of heat transfer. Below will be presented some examples of conduction quite often that you encounter in everyday life, among which are:
1. Conduction can occur when someone is ironing. When you are ironing clothes, you need the heat of the iron to make the job easier. The heat from the iron will cause heat transfer when it comes into contact with the clothes. However, not only clothes, all things that have conductive properties can be heat transfer, including human skin.
2. Conduction can occur when someone stirs a hot drink. If you dip a spoon with stainless steel material into a glass filled with hot tea water, then the tip of the spoon that is not dipped will also experience heat transfer with a hot or warm feeling. This can happen due to the transfer of heat flow from the original high temperature part to the low temperature part.
In addition to the two illustrations above, there are some simple examples that you often experience in your daily activities, including:
- Hands blistered when holding a hot wok.
- When cooking, the tip of the spatula will feel hot even though it is not in direct contact with the flame.
- When the hot iron is rubbed against the shirt, then the shirt will be neat and warm.
- When hugging a person who has a hotter temperature, the body will feel warmer.
- The old exhaust gets hot when the engine is turned on.
- A metal spoon that is used to stir hot tea, the end of the spoon that is held becomes hot because the other end is in direct contact with the tea.
- A cup that feels hot when filled with hot water.
- A plate that feels hot when used to put hot food.
- Heat food using a wok.
- The heated butter becomes melted because it absorbs the heat sent through the wok.
- Ironing clothes. Conduction occurs on the metal-based iron surface.
- The lid of the pot becomes hot when used to cover the boiling water.