Magnetic Flux and Magnetic Flux Density Units (1 Viewer)

[Web Addict]

Hi.

This question was from my half-yearly exam for Physics:

Which alternative correctly identifies the unites for magnetic flux and magnetic flux density?
Magnetic Flux Magnetic Flux Density
A. Tesla Tesla
B. Tesla Tesla per metre square
C. Tesla Tesla per second square
D. Tesla per metre square Tesla

My class is having a debate on whether the answer B or D. I tried searching for the answer in some textbooks, but couldn't find anything. The units are all in terms of Weber, not Tesla. Do you guys know what the correct answer is? If you can, can you please provide me with the source?

Thank you.

Edit: Sorry about the format of the options of the question. I couldn't find the tool for a table.

 

[skillstriker]

magnetic flux density = magnetic field strength, so it should be measured in Tesla
magnetic flux = BA, so shouldn't it be tesla metre square

 

[someth1ng]

D is the most correct, as above, none are technically fully correct.

Poor question, they should change all of the "Tesla" to "Weber" but then the correct answer would be B

 

[Web Addict]

So is the unit for magnetic flux Tesla metre square (Tm^2), not Tesla per metre square (T/m^2)?

During the test, I was stumped on this question and I just thought that it was a typo. I thought he meant Weber instead of Tesla, so I ticked B.

Originally, my teacher took the correct answer as B, but he then changed it to D. That would mean that I would be losing one mark, unfortunately.

 

[someth1ng]

So is the unit for magnetic flux Tesla metre square (Tm^2), not Tesla per metre square (T/m^2)?

During the test, I was stumped on this question and I just thought that it was a typo. I thought he meant Weber instead of Tesla, so I ticked B.

Originally, my teacher took the correct answer as B, but he then changed it to D. That would mean that I would be losing one mark, unfortunately.

Technically, magnetic flux can be measured as Tm^2 but that's really not the right way to do it - it should be Wb.

You should argue that D is also the wrong answer.

Magnetic flux density: Tesla (Wb/m^2)
Magnetic flux: Weber (Wb)

 

[Web Addict]

Ok. Cool. So none of them are correct. That means I can argue and hopefully I won't lose that marks.

 

[Fizzy_Cyst]

None of them are correct.

The question needs to be taken out of the paper.

 

[ProtoStar]

Since Flux density is Tesla = Wb/m^2, and Flux is Wb = (Wb/m^2)(m^2) = Tesla(m^2) shouldnt the answer be D?

 

[Web Addict]

D says that the unit for magnetic flux is Tesla per metre square (T/m^2), therefore it is incorrect.

 

[SophxMusic]

Magnetic flux density is a measure of Tesla per unit area.
Magnetic flux is simply the amount of 'lines of force' (Faraday's term, not mine) that pass through a specific area. So if you are given an area and a magnetic flux density you can calculate the amount of magnetic flux passing through that specific area. Magnetic flux = magnetic flux density x area
Because magnetic flux density is measured in tesla/unit area, if you multiply by area you are simply left with an answer with the unit Tesla.
Magnetic flux density = tesla/unit area
Magnetic flux = tesla

 

[SophxMusic]

the correct answer is B...

 

[Web Addict]

B would be correct if the units were in terms of Weber, not Tesla.

 

[RealiseNothing]

None are correct, it should be "Tesla metre squared, Tesla"

 

[SophxMusic]

webaddict and realise nothing, I'm not trying to sound arrogant but I'm speaking from both what my teacher has told me and what has been confirmed in the excel book... tesla is the same as weber/m^2, except the question is not asking for it in terms of weber. B is the correct answer, as it asks to give the units for 1. magnetic flux and 2. magnetic flux density
Magnetic flux density is the same as magnetic field strength, or (B). It is a measure of the amount of flux lines passing through each unit area - tesla per unit area, or in terms of this question, per metre square
Magnetic flux, by mathematical definition is the product of B (in Tesla/unit area) and Area (in unit area)
If you multiply these two terms the 'divided by' and 'multiplied by' areas cancel out and you are left with Tesla..... maths works with units as well. It's the same as velocity, which measured is measured in m/s.... how do you find velocity? Divide distance (metres) by time (in seconds)...
I state again, correct answer is B. It asks for Tesla, so use Tesla, don't get confused by trying to convert weber/m^2. They are equivalent units.

 

[SophxMusic]

Self proclaimed ass here... I apologize profusely for before, I'm mistaken. I double checked from other sources and have realised I'm wrong...
Shall be having a nice word to my physics teacher after our half yearly tomorrow morning :/

 

[RealiseNothing]

Self proclaimed ass here... I apologize profusely for before, I'm mistaken. I double checked from other sources and have realised I'm wrong...
Shall be having a nice word to my physics teacher after our half yearly tomorrow morning :/

hahah nah dw, it's the internet anyway, doesn't bother me.

 

[RealiseNothing]

So web addict, there is no correct answer. Tell your teacher that I suppose, it should be Tesla metre squared ().

 

[Web Addict]

Thanks, guys. I just had an argument with my teacher today and he finally agrees with me that no answer is correct. I guess I'm not losing that mark then. Thanks again.

 

[RealiseNothing]

Thanks, guys. I just had an argument with my teacher today and he finally agrees with me that no answer is correct. I guess I'm not losing that mark then. Thanks again.

Congrats