impedance

[Andy™]

Applaud Smiley:^ODoes your's say 'keep right' every now and again on a motorway, just as a generally reassuring break to the radio?

yes, but i often get used to ignoring the 'keep right' & 'keep left' until its too late and have to go turn round....

 

[Apache]

yes, but i often get used to ignoring the 'keep right' & 'keep left' until its too late and have to go turn round....

lol. I tend to mute her if I know where I'm going

 

[Andy™]

lol. I tend to mute her if I know where I'm going

Do you love the voice of Jane so much you have to listen to her when you know where your going?!

 

[Apache]

Do you love the voice of Jane so much you have to listen to her when you know where your going?!

yes. I like the countdown of time, re-route if have to leave motorway etc

Saw the real Jane on the TV. She doen't look as I imagined

 

[Andy™]

yes. I like the countdown of time, re-route if have to leave motorway etc Saw the real Jane on the TV. She doen't look as I imagined

I would imagine there is more than one Jane on TV these days... sure you got the right one?!

 

[Apache]

I would imagine there is more than one Jane on TV these days... sure you got the right one?!

no it was the voice actress who voiced Jane. Middke adged frumpy woman

 

[Jono Pashley]

no more calculations after midnight for me

 

[Jono Pashley]

Z=√R

 

[SPECIAL LOCATION]

id be lost without my calculator!

You don't need a calculator for this question...

It is a basic 3-4-5 right angle triangle..

as are 90%+ of city & guilds questions..

so you can work them quick & get the answer done during the exam!

"a capacitor of capacitive reactance 50, an inductor of 80 inductive reactance and a resistor of 40 are connected in series to a 200 50Hz supply. the impedance of the circuit will be ?"

supply voltage & frequency are red-herrings just to throw you!

C&G are just trying to see if you understand the concept of the

"Impedance Triangle" & the relationship between Resistance / Inductance / Capacitance / Impedance.

e.g.

as Nicky said on post #2

Inductance & capacitance are the vertical lines working in opposition to each other.. 80 - 50 =30

The resistance is the horizontal line 40 (at right angles to vert Ind/Cap value)

so a triangle has two right angled sides 40 & 30...

The diagonal MUST be 50!!!

basic school maths..

Pythagoras theory..

square on the hypotenuse is equal to the square of the sum of the other two sides..

5x5=25

4x4=16

3x3=9

9+16=25

ANY triangle with proportions 3,4,5 will BE a right angle!!!

These proportions are used LOADS of times by city & guilds..

so the calculation part is quick and easy..

All they want to know is if you understand the concept NOT if you can use a calculator!

e.g.

as 3, 4, 5 is a right angle triangle..

so is 6 , 8, 10... {2 times proportions}

or 9 , 12, 15... {3 times proportions}

or 12, 16, 20... {4 times proportions}

or 15 , 20, 25... {5 times proportions}

...

etc..

etc...

and of course... 30, 40, 50 {10 times proportions}

doing the angle bits or leading or lagging may need a calculator..

unless you can also remember that a 3,4,5 triangle has angles of

36.87,

53.13

& 90 degrees!

but that another question.