Q 26, transformer (1 Viewer)

[moderf]

26. a) Which arrangement would produce a spark when the power supply is turned on? Justify your choice. 1 mark

b) Explain how different voltages are induced when the secondary coil is moved to different positions. 2 marks


how do u do this quesitonf? i had to make up stuff 4 this question.

nd in the question, it says something abt the how the position of the secondary coil determines the length of the iron core. how is that going to affect the induced voltage?

 

[Shadose]

The one that has the 2ndary coil being able to induce a current from the fluctuating primary coil. ie i think the 1st one

 

[bazookie]

yessss the first one....

the secondary coil needs to be over the primary coil

 

[ashbashness]

Vs/Vp=Ns/Np

therefore Vs=Vp*Ns/Np

effectively as I understood it, the question was asking you to change Np by moving the primary coil in and out, so a lower Np would cause a bigger Voltage in the second. That's what I put. No idea if this is how you go about it. Has anyone tested it?

 

[runnable]

I said the second one because that one has less Np within the secondary coil.

 

[adnan91]

I said the second one because that one has less Np within the secondary coil.

YESSSSSSS thats what i put. It made perfect sense cuz the secondary coil would have more turns than the primary coil and thus produc a greater voltage.

 

[layzeehbum]

26. a) Which arrangement would produce a spark when the power supply is turned on? Justify your choice. 1 mark

b) Explain how different voltages are induced when the secondary coil is moved to different positions. 2 marks


how do u do this quesitonf? i had to make up stuff 4 this question.

nd in the question, it says something abt the how the position of the secondary coil determines the length of the iron core. how is that going to affect the induced voltage?

i think i put the first arrangement.... and i also hav 2 make a lot of bull for the rest of the questions =)

 

[iEdd]

I said the second one because that one has less Np within the secondary coil.

Okay, so by that logic, I can make a loop of wire and it has infinite volts in it, because there is no primary coil, hence the secondary coil is divided by zero = infinity.

It was the first arrangement. The second won't even - or *shouldn't* transfer enough magnetic flux for induction to occur. If it did it would be fairly inefficient.

 

[dolbinau]

Vs/Vp=Ns/Np

therefore Vs=Vp*Ns/Np

effectively as I understood it, the question was asking you to change Np by moving the primary coil in and out, so a lower Np would cause a bigger Voltage in the second. That's what I put. No idea if this is how you go about it. Has anyone tested it?

I wasn't sure about that either. It sounds right I guess, I think I got that completely wrong now that I think about it - I talked about changing flux and the iron core magnifying the magnetic field. Sounds completely wrong.

 

[jasonml]

Strictly speaking both will cause a spark to jump through, although the setup with one solenoid inside the 2nd, will induce a much greater emf.

 

[runnable]

The 2nd arrangement had SOME primary coil in it. Just because you can't see it doesn't mean its not there. Just like you can't see the primary coil in the first arrangement, but you assumed it was there.

The less primary coil in the circuit, the greater the induced voltage in the secondary coil.

 

[Js^-1]

Strictly speaking both will cause a spark to jump through, although the setup with one solenoid inside the 2nd, will induce a much greater emf.

Not necessaarily. It might have the required voltage to jump across, and it might not. We have one at our school that we use and the spark starts jumping when you put it about halfway across.

 

[Aaron.Judd]

Setup A.

 

[2S1D3]

I said the second one because that one has less Np within the secondary coil.

Exactly what I put.

 

[jasonml]

all depends on imput voltage. did they give us that? i cant remember

 

[iEdd]

No... The input voltage is the same for each so it's irrelevant.

Either arrangement has the same amount of primary coils conducting, and to flow through the secondary coil, all coils must also conduct. All that's being varied is how many secondary coils are exposed to magnetic flux. I think it might be just adjusting the efficiency more than anything.

 

[jasonml]

i'm saying the setup with the primary outside of the secondary would induce a small, but nonetheless existant emf, thus if voltage was high enough (across both) a spark will jump across both.

 

[iEdd]

Oh I get what you mean now, yeah. If the coils weren't overlapping, I guess there would still be some flux transfer and there might be a spark.

 

[whatever1000]

I said A setup B didn't even look like it was on the primary coil, I just answered i guess from an induction coil in class I swear I have never seen one how it was in the second setup.

 

[munchiecrunchie]

I've actually used this apparatus (the induction coil) several times in physics prac lessons, and it was definitely the 1st setup that allowed for the sparking. As you move the coil outwards, the sparking decreased, so yeh definitely setup A.