(a)(i) With the aid of a simple diagram, explain information transmission. (ii) Give one example of information transmission. (b) Give one example of each o...

(a)(i) Information transmission is the process of sending information (a message) from one point (the source) to another point (the destination) through a communication channel. The sender encodes the message into a signal, the signal travels along a transmission medium, and the receiver decodes the signal back into the original message.

A simple diagram of information transmission:

As shown above, the source/sender encodes the message into a signal; the transmission medium (channel) carries the signal to the far end; and the receiver/destination decodes the signal back into the original information.

(ii) One example of information transmission is sending an SMS text message over a GSM network (other valid examples include receiving radio or DSTV signals, printing a document, and classroom instruction).

(b)

(i) An example of a single-user single-tasking operating system is MS-DOS (also PC-DOS or Palm OS).

(ii) An example of a single-user multitasking operating system is Microsoft Windows (also Mac OS).

(iii) An example of a multi-user operating system is UNIX (also Linux, Xenix or VMS).

(c) Four features of a Graphical User Interface (GUI) are:

1. Windows - rectangular on-screen areas in which programs and documents are displayed, allowing several tasks to be viewed at once.
2. Icons - small pictures that represent files, folders, programs or commands, selected by clicking.
3. Menus - lists of commands or options from which the user chooses, removing the need to memorise typed commands.
4. Pointing device (mouse) - a point-and-click device used to move the on-screen pointer and select items.

(These four features are often remembered by the acronym WIMP: Windows, Icons, Menus, Pointer.)