# stuck on new specimen physics HL Q7a

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New specimen physics HLpaper2

Question 7a determine the maximum emf induced in the coil

The markscheme says the answer is 3.2mV. I keep getting 0.3mV

I found the gradient B/t  and used the BAN formula.

What did I do wrong?

Edited by bluemoon
forgot to mention which paper

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3 hours ago, bluemoon said:

New specimen physics HLpaper2

Question 7a determine the maximum emf induced in the coil

The markscheme says the answer is 3.2mV. I keep getting 0.3mV

I found the gradient B/t  and used the BAN formula.

What did I do wrong?

Your answer 0.3mV is correct, the mark scheme is wrong. There are lots of other mistakes in the markscheme ( and the questions actually, for example Q5dii). So if you took the slope at any point where the graph cuts the x-axis and used (slope)*AN then you have done it correctly.

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Yeah and in question one or two where you had to use the formula pi r^2 to calculate the Area, they used the diameter instead of the radius...

They probably want us to get confused... Even when those people, who write the exams, produce wrong mark schemes (and it's not just one or two mistakes, it has a lot!!), how can they expect from us to solve them?

In my opinion, it would have been much better, if they would have taken a look at the mark scheme just once more...

And the BIGGEST problem is, when the mark scheme for the final exam has mistakes and our exams get wrong corrected... This would be the peak...

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Thanks for help, really appreciate it.

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1 hour ago, Moma said:

Yeah and in question one or two where you had to use the formula pi r^2 to calculate the Area, they used the diameter instead of the radius...

They probably want us to get confused... Even when those people, who write the exams, produce wrong mark schemes (and it's not just one or two mistakes, it has a lot!!), how can they expect from us to solve them?

In my opinion, it would have been much better, if they would have taken a look at the mark scheme just once more...

And the BIGGEST problem is, when the mark scheme for the final exam has mistakes and our exams get wrong corrected... This would be the peak...

There were also quite a few mistakes in the markscheme for paper 3.

Don't worry about the final exam, because, according to my teacher( which is an examiner) the markscheme can be edited during the marking if examiners find any mistake.

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35 minutes ago, bb8-m8 said:

There were errors on the chem specimen paper 2 as well...

Yeah, the one about determining the IHD of that molecule for SL paper 2. Actually there were also errors in the biology specimen, according to some student in my class. For some reason I feel that they have done this intentionally.

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Do all specimen papers' mark schemes have mistakes?

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1 hour ago, iblearner said:

Do all specimen papers' mark schemes have mistakes?

Errors are not intended. The specimen papers' primary audience is teachers, who are looking for guidance to structure their lectures and worksheets rather than students who want to practise. So far I have heard about mistakes in the physics, biology, and chemistry specimens for 2016 and onward. The review and audit process for actual exams are quite rigorous. In the occasional times when errors have been identified, usually as two or more correct multiple choices, all correct answers are acceptable. Markschemes are subject to updates as they receive students' and teachers' responses.

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On 4/7/2016 at 11:11 PM, Haitham Wahid said:

There are lots of other mistakes in the markscheme ( and the questions actually, for example Q5dii).

Hi

What was wrong with the question (Just wondering) ?

Edited by Jai Chandak

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16 minutes ago, Jai Chandak said:

Hi

What was wrong with the question (Just wondering) ?

The energy released in the fission reaction is E = mc, where m is the difference in mass between the reactants and the product. Since energy is released the reactants must have higher mass than the products (otherwise energy will be required for the reaction to occur). From the data provided, you can calculate m to be -0.816u, which is less than zero. Therefore, Energy is required for this reaction, which contradicts the fact the energy was released. Therefore something is wrong with the data provided or the reaction itself.

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8 hours ago, Haitham Wahid said:

The energy released in the fission reaction is E = mc, where m is the difference in mass between the reactants and the product. Since energy is released the reactants must have higher mass than the products (otherwise energy will be required for the reaction to occur). From the data provided, you can calculate m to be -0.816u, which is less than zero. Therefore, Energy is required for this reaction, which contradicts the fact the energy was released. Therefore something is wrong with the data provided or the reaction itself.

Agree
Wikipedia says rest mass of La-148 is 147.932 u instead of 148.932.

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Hello, what about paper 3 imaging, 13 (a) (ii)? Shouldn't they use the equation for magnification of the image at near point (1 + D/f) rather han just for an image at infinity (D/f)?? plz help :c I keep getting 429, whereas the answer is 380.

Edited by Skania

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