Try this !

[daiplayer]

R= 100 ohms , Xl = 200 ohm , Vs = 200 Vac, .....Vr = ??? and Vxl = ?????

 

[daiplayer]

im not trying to cheat..lol...i got Vr = 39.5v and Vxl = 79v........really aint sure if its correct

 

[telectrix]

R= 100 ohms , Xl = 200 ohm , Vs = 200 Vac, .....Vr = ??? and Vxl = ?????

series or parallel?

 

[daiplayer]

series...:-? ...pretty sure i got this wrong...if you know this...could you explain please ....:-?

 

[pushrod]

series...:-? ...pretty sure i got this wrong...if you know this...could you explain please ....:-?

I'm thinking... in series so current is same thru both

Calc Z using pythagoras =223Ω

calc current from I=V/Z = 0.89A

calc Vl = I x Xl = .89 x 200 = 178V

calc Vr = I x R = .89 X 100 = 89V


mind it is still very early for me lol!

 

[daiplayer]

ok...think we both got it wrong here. lol....i got Z= 223 ohm....therefore current (v/z) = 0.35A

Vr = IxR = 35.7 v
Vxl = 71.54 v ....?????

 

[pushrod]

ok...think we both got it wrong here. lol....i got Z= 223 ohm....therefore current (v/z) = 0.35A

Vr = IxR = 35.7 v
Vxl = 71.54 v ....?????

Wasn't Vs 200V? so I = V/Z = 200/223 = 0.89A?

You would need a voltage of 78.5V to have a current of 0.35A

 

[pushrod]

As a check try... Vs = √(Vl²+Vr²)

One of our answers works, the other doesn't!
guess whose works





Edit: 114 views so far no one else going to give an opinion???

 

[daiplayer]

sorry mate...the question was Vs 80v.....i wrote 200v on here. So i assume you are correct too !!! lol .

 

[pushrod]

sorry mate...the question was Vs 80v.....i wrote 200v on here. So i assume you are correct too !!! lol .

Guess that does kinda make it harder for me to get the right answer LOL

ah well at least you got confirmation of the method and i was at least able to think straight early on a sunday

 

[telectrix]

not a lot of difference there, only a measly 120v. enough to run a sds drill on. no wonder answers are different.

 

[telectrix]

pushrod, please xplain calculating Z by that old greek geek. done this theory once but it was 40 years ago.

 

[daiplayer]

z= sqaure root of ( r sqaured + x squared)

 

[pushrod]

pushrod, please xplain calculating Z by that old greek geek. done this theory once but it was 40 years ago.

Just about to post and i lost it all

easier to explain if i could draw on this

imagine a right angle triangle with long side (hypotenuse) of 5 and the other two sides of 4 and 3.
The theory is "the square of the hypotenuse is equal to the squares of the other two sides added together"

So 5² = 25

and the other two sides are 3² + 4² =25

In this case Z (the impedance is the hypotenuse) and the other two sides were R (resistance) and Xl (inductive reactance)

So Z² = R² + Xl²

and rearranged Z = √ R² +Xl²

Know any two and you can work out the third one

usually right angled triangles are all simple multiples of 3, 4 and 5
eg 6, 8 and 10; 9, 12 and 15 etc etc

(better post it before it all disappears again)


Edit: The wiki explanation is a bit dry THIS is dead straight forward.

 

[TPES]

This is a blast from the past!