convection requires a medium is not the main difference, it is simply the most obvious aspect of what is a fundamentally different mechanism for transfering energy. Convection is the transfer of energy by movement of a medium, whereas radiation is the transfer of energy by, well, thermal radiation. Conduction also requires a medium, but, again, it is a fundamentally different mechanism than either convection or radiation; in this case it is the transfer of energy through a medium.
Unfortunately, analogies are hard but if you can visualize the particles involved, it would help. Picture the red hot iron you mentioned. On a molecular level, the material is emitting lots and lots of photons (hence why it is glowing red). The creation of these photons takes energy; energy from the heat of the iron. These photons leave the iron, pass through the environment, and eventually collide with some other object where they are absorbed and deposit their energy. This is radiative heat transfer. If that energy is deposited on your retina or a CCD (like in a digital camera), an image forms over time. This is how infrared goggles work and they would work equally well in high vacuum as here on earth.
In conduction, the next simplest example, there is no generation of photons (physics nerds forgive me for the sake of simplicity). The individual atoms in the object are vibrating with heat energy. As each atom gains energy from it's more energetic neighbors, so it gives up energy to its less energetic ones. Over time, the heat "travels" through the object.
In convection, the molecules of gas near the object gain energy, like in the conduction case, but those same molecules that gained energy then travel through the environment to some other location where they then give off their heat energy.
In summary:
radiation = generated and absorbed photonsconduction = molecules exciting their neighbors succesivelyconvection = molecules heated like in conduction, but then move to another location
Safety Data sheet gives information about the product imported in a form of a document. Importers and manifacturers make these Safety Data sheet to detail the product of its physical and chemical properties which are hazardous and harmful. This is a safety protocol on every company.
Answer: B) Transport layer
Explanation:
The transport layer is basically responsible for the flow control and detecting the error recovery between the system.
In the open system interconnection, the transport layer are responsible for transferring of data independently along with the congestion control, flow control, segmentation and error control.
And the presentation layer, session layer, physical layer and application layer in the OSI model are nor responsible for the flow control in the network system.
Therefore, option (B) is correct option.
Answer:
Choosing the style of a table
Adding colored borders to a table
Adding borders to separate the cells
