This is ridiculous!
a highly melodramatic cry for help demanding "immediate help" on entry level basic engineering questions with posts written in text speak, initial thoughts:
1. Why Immediate help, left your homework too late and struggling? or
2. Too lazy to do your own work
3. and any engineer who communicates in text speak should be thrown out of the industry for failing the basic ICAO requirement to be able to "communicate both orally and in writing in English" even worse since you have to actually use a computer to post on here!!!!!
If you cant answer questions like this at your stage of training, I.E you have an exam on this subject, and you cant even do basic research, and you think the way you've posted on here is ok, then I really hope I never have to work with you!
No wonder the accident statistics for aviation are not going down!