Answer: B webcast
Explanation:
A webcast is a technology that allows the live broadcast of an audio or video event on the Internet. It is also known as Web lecture, virtual meeting, etc. The major advantage is that it gives room for an event to have a larger reach. Webcast participation can be through PC, smart phones, tablets and other devices with quality Internet access.
The answer is Portrait, or Option Choice C.
Diagonal can be relative to any shape
Sideways can be relative to any shape
Portrait is usually more vertical than horizontal because it is used to depict a person, usually stopping at the bottom of the torso
By process of elimination, Landscape is the answer. Also, its because Landscape is usually used to depict the Land scape. What a surprise. And as you know, their is only so far you can paint vertically , but there is much more to paint horizontally. Making the canvas more horizontal than vertical.<span />
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
The security countermeasure that one can enable on a wireless access point as part of the layered solution for WLAN implementations would be to disable 802.1x . It is the one that provides a WEP and is very unsecure. Another is to change the SSID and to set the broadcast of the SSID to off.