The Hall effect, named after the man who discovered it, describes the effect when a conductor carrying current is subjected to a magnetic field. Under these circumstances, a small voltage is generated at right angles to the direction of current flow. This is known as Hall voltage, Vh.
An incandescent light bulb is a glass envelope filled with gas, with a wire filament inside it. When electricity is passed through the filament, it becomes white hot. This is heat in the visible range. As the filament burns, byproducts evaporate off it and deposit on the inside of the glass tube. After a certain period in service, the filament either breaks or simply burns away completely, and the bulb burns out.
A halogen lamp is also an incandescent light, but the gas in the envelope is halogen and the filament is made of tungsten. Again, when the lamp is on, the filament gets white hot and begins to burn, but the halogen gas captures the evaporating tungsten and deposits it back on the filament. Thus a halogen light bulb will last quite a lot longer than the average incandescent bulb.
Advantages of Halogens:
They operate at much higher temperatures, so they burn brighter (they are more powerful).
They glow white hot in operation, at much higher temperatures than equivalent bulbs, so their light is much more natural looking. Conventional incandescent bulbs burn at much lower temperatures and give off more 'yellow' light.
Because the halogen gas deposits tungsten back on the filament as it burns, halogens last much longer than equivalent bulbs.
Hard disk drive
All data, information, documents, photorgraphs etc. that live in computer memory are lost the instatnt the machine is switched off. Any data that needs to be kept for further use must be saved to the hard disk. Any data saved to the hard disk can be retrieved and loaded back into memory (RAM) at any time. As well as storing data, hard disks also store the computer operating system. In the case of the C.P. Section, this is Windows Professional XP. As well as an operating system, the computer also needs various programs like Word and Excel. The size of hard disks varies-in other words their storage capacity varies. Their physical size stays the same so that the hard disk from one machine can be mounted in another. Most hard disks connect to the motherboard using the ATA standard (IDE). Two drives can use the same connecting cable. As long as one is designated Master and the other as Slave, there will be no problems. As of mid 2006, the new Serial ATA (SATA) standard is now almost universal. It is faster than the ATA standard. There is only one SATA drive per connection to the motherboard, so there is no need to designate master and slave drives.
Please note, if you want to contact the main Training Centre in Baldoyle, you need to ring 01-8167400.
If you want to contact the CP Fitters' Section, you can Contact Us by email, email@example.com, or by telephone: 00 353 1 8167543 This number gets you through to the CP Fitters' Section, Baldoyle Satellite Unit.
Is Féidir Linn! You can view all the menus on this site as Gaeilge by going to the homepage, top right hand corner, and dropping down the language selection menu. By default it reads English (en), so just select Gaeilge (ge) instead.