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[manly girl]

My Notes: Transmission Media

This is from my IT background, but I found it very usefull in telecommunications. If you want me to expand on any dot point, just ask.


:: PHYSICAL CONNECTIONS
Called Transmission Media
Used to Join the components of a LAN.
Can be cable or wireless.


:: TWISTED PAIR CABLE
(TP) consists of two copper insulated wires entwined around each other.
Can be UTP or STP (see below)
Known as signal and return paths.
Analog or digital
Twsiting the cables reduces crosstalk (Electromagnetic interference between the two)
Range is limited to 100's of metres.


UNSHIELDED TWISTED PAIR CABLE (UTP)
Consists of a pair of twisted wires with a simple plastic encasement.
Widely used in telephone systems.
Inexpensive and widely avaliable.
Easy to install.
Can support data rates of up to 100Mbps @ 100m, however most common rate is 10Mbps.
High attenuation rate
Very susceptable to EMI (Electromagnetic Interference)
Not very secure


SHIELDED TWISTED PAIR CABLE (STP)
Metal foil insulator wrapped around twisted cables.
More expensive than UTP.
Easy to install with preconfigured cables
Supports up to 155Mbps, but most common is 16Mbps. (Speeds up to 500Mbps @ 100m)
High attenuation rate.
Some EMI
Not very secure.


:: COAXIAL CABLE
A hollow outer shielding that surrounds a single inner wire core.
Core carries signal, shielding acts as the return path
Low speed digital uses 50ohm cable
High speed digital/analog uses 75ohm cable
Thin cable costs less than STP
Thick cable costs more than STP
Both cost more than UTP
Simple Installation
Transmit 10Mbps (digital) and 400Mhz (analog)
High attenuation rate.
Effective range 2km.
Quite secure.


:: FIBRE OPTIC CABLE
Signals are converted into light and sent.
Fibre Optic consists of core (carries light), cladding (surrounds core) and coating (protects cladding).
Core and claddign are both glass.
Expensive
Difficult to install
Up to 2Gbps up to 25km.
Low attenuation.
Immune to EMI
Very secure
Digital and analog.


:: WIRELESS LAN
Low installation costs, even though equipment is still expensive
Easy to install
Portable
A wirless connection can be made to an existing LAN.
Uses transcievers (transmitter / reciever)

 

[Scabbage]

Material Website

If you haven't gone to this yet...

here is a good website that outlines Materials and stuff...

http://info.lu.farmingdale.edu/depts/met/met205/index.html

 

[tieki]

Civil Structures summary...

Hey everyone - the main website isn't putting any new items up until the new site is online, so in the meantime, here's a summary on civil structures I did

 

[McLake]

Energy:
Potential Energy (PE)
PE = mgh (in J)

Kinetic Enegry(KE)
KE = 1/2(mv^2) (in J)

Other types of energy include Spring Energy (SE). These are not in the course.


Power:
Work (W)
W = Fx (in J)

Power (P)
P = W/t = Fx/t = Fv (in W)

(edit by inasero)_____

According to the law of conservation of energy, "energy is neither created or destroyed, it is merely transformed into alternative forms". When your car motor is running, chemical energy within the hydrocarbon fuels is released with combustion and converted to oscillating linear motion of the pistons which is then transformed into rotary motion through the action of a crank mechanism.

When an object is placed on top of a ramp and stationary it has zero kinetic energy (energy due to movement) and 100% gravitational potential energy (energy due to an object's positioning in relation to the Earth).

Let's give the object a little nudge to get it moving. It's now at the botttom of the ramp. It's important to note that the GPE has not entirely been converted to KE, because the object is still above the centre of the Earth. Nonetheless alot of GPE is now converted to KE (with a little loss of course due to heat loss through friction).

A cool thing happens if you equate the two formulae for GPE and KE:

mgh = 1/2 mv^2
gh = 1/2 v^2
2gh = v^2
v^2 = 2gh
v = sqrt(2gh) (take the positive square root in the direction of motion)

So, by equating these thwo formulae you can determine the velocity of an object at the bottom of the ramp (but ONLY is we assume it is frictionless. This will usually be stated explicitly or worked implicitly into all HSC questions).

 

[Garick]

http://www.jhu.edu/virtlab/bridge/truss.htm

you better put this to good learning use.

i grabbed it throught the enginerring section of http://www.hsc.csu.edu.au

that site a lot of good questions to check your knowledge on the course. It has answers as well.

 

[inasero]

http://www.dayah.com/periodic/
IMHO, one of the most comprehensive periodic tables available freely on the net...

 

[inasero]

Heat Treatment

This is about all you are required to know for the syllabus in regards to heat treatment processes...good luck~

 

[inasero]

Personal and Public Transport

If you browse through past years HSC papers you will notice that examiners like to ask generic questions which relate to the focus module.

For example, in the PPT module, Question 13 of the 2002 HSC examination asks: "Many people support the continued development of alternative transport solutions to overcome problems in cities. Discuss an environmental issue and a social issue associated with the ongoing development of electric transport".

This leaves you with the scope to discuss a variety of transportation methods. Choose one early on in the year and stick to it. Do NOT change your choice halfway through the HSC exam.

I'll post up my focus of this module for everyone to browse through. Alternatively you might want to choose a different focus such as ships or planes (planes have the added advantage that you will consolidate your knowledge for the Aeronautical Engineering module, but is harder to talk about since the field is so varied).

(other parts of the report to come soon)

 

[inasero]

Useful links for Aeronautical Engineering

http://www.ueet.nasa.gov/Engines101.html
http://www.centennialofflight.org/index.cfm
http://www.geocities.com/nedu537/turbine/
http://www.grc.nasa.gov/WWW/K-12/airplane/short.html

 

[MoNNiE]

don't be fooled by file name.. 11/12 of it is missing

umm i dunno what happen to the rest of it!.. but yeah.. that's all i had left for some reason

 

[kofmaster]

Hey everyone - the main website isn't putting any new items up until the new site is online, so in the meantime, here's a summary on civil structures I did

istead of half-yearly summary do u have a summary of all the modules

 

[MoNNiE]

i'm rather lazy to dig it up..
but someone had asked for more questions regarding mechanics - in particular trusses..

i've scanned some questions out of my Statics book i'm currently using for University..

if you don't get the answers for some of them don't panic! some of the questions i think are hard to figure out, even for myself!

taken from: Engineering Mechanics: Statics 5th edition SI version (J.L. Meriam & L.G. Kraige)


truss analysis - has some good information, though you might want to shift through alot of irrelevent stuff to the hsc

 

[Lucent]

http://www.dayah.com/periodic/
IMHO, one of the most comprehensive periodic tables available freely on the net...

I appreciate the compliment.

 

[djmike]

thanks 4 the notes
grate help since im sick and cant do my own

 

[Karen116]

thx very very much...
Nearly the 1st assessment ....
Good review...
Thxs

 

[cwag]

here are the worked solutions for 04, 05, 06, and 07 engineering HSC papers.

View attachment 17185
View attachment 17186
View attachment 17187
View attachment 17188

 

[Triple777ER]

here are the worked solutions for 04, 05, 06, and 07 engineering HSC papers.

View attachment 17185
View attachment 17186
View attachment 17187
View attachment 17188

Thankyou so much for those solutions. Have been looking a lot for these.
This will definitely help my revision a lot.
Thank you so much once again and good luck

 

[cwag]

no worries....except i have found a few mistakes...like 07 question 13 (ii) the infamous distance going up hill question....i don't think their answer of 5 something is right....i believe you equate loss in kinetic energy = gain in potential...thus mgh=1/2mv^2 therefore h = v^2/2g where h is vertical distance....using trig ratios u come up with your distance....i think its 28.1m

but yea..i don't know how reliable they are...but they are better than nothing

heres 02 as wellView attachment 17195

 

[Triple777ER]

Yeah, i did that question before i had a look at the solutions. i got 28.1m as well. They are quite good, as you said its better than nothing, but the forming processes are out of the syllabus.

And here are the 2003/02/01 band 6 ansrwers. http://arc.boardofstudies.nsw.edu.au/go/hsc/std-packs/

 

[so0wank]

Hey umm do you have answers to the 08 HSC paper? Really need it and fast!.><