Edexcel Physics Unit 4: Physics on the Move 6PH04 01 - 15 Jun 2017

anyone able to explain answers to i) ii) iii)

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Original post by Gintama-kun

anyone able to explain answers to i) ii) iii)

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So for (i) its to do with electromagnetic induction, since the plane is moving in a magnetic field this would result in the earth's magnetic flux being cut. The change in magnetic flux induces an emf in the plane wings, and the free (delocalized) electrons in the plane wings start to move.

For (ii) We use the fleming's right hand rule since it is generator effect/ flux is being cut (The right hand rule is used to identify the direction of an induced emf, but the left hand rule is used for the motor effect) . Its quite difficult to twist your hand for this question, but if you manage to do it, you will see that the induced emf points to the 'right side' of the plane wing. Do know the plane is coming out of the paper so motion is out of the paper, and the magnetic field, that is given to u in the diagram.

For iii) i got only one mark by saying: there is no change in magnetic flux linkage as the plane is moving at a constant rate. ( this is because according to Faraday's law the magnitude of induced emf is proportional to the change in magnetic flux linkage, so since speed is constant here then there is no change)
i couldnt quite understand the answer provided by the markscheme.
Link below
http://pmt.physicsandmathstutor.com/download/Physics/A-level/Past-Papers/Edexcel-IAL/Unit-4/January%202014%20(IAL)%20MS%20-%20Unit%204%20Edexcel%20Physics%20A-level.pdf

Reply 24

Gintama-kun

Original post by BenedictOdai

So for (i) its to do with electromagnetic induction, since the plane is moving in a magnetic field this would result in the earth's magnetic flux being cut. The change in magnetic flux induces an emf in the plane wings, and the free (delocalized) electrons in the plane wings start to move.

For (ii) We use the fleming's right hand rule since it is generator effect/ flux is being cut (The right hand rule is used to identify the direction of an induced emf, but the left hand rule is used for the motor effect) . Its quite difficult to twist your hand for this question, but if you manage to do it, you will see that the induced emf points to the 'right side' of the plane wing. Do know the plane is coming out of the paper so motion is out of the paper, and the magnetic field, that is given to u in the diagram.

For iii) i got only one mark by saying: there is no change in magnetic flux linkage as the plane is moving at a constant rate. ( this is because according to Faraday's law the magnitude of induced emf is proportional to the change in magnetic flux linkage, so since speed is constant here then there is no change)
i couldnt quite understand the answer provided by the markscheme.
Link below
http://pmt.physicsandmathstutor.com/download/Physics/A-level/Past-Papers/Edexcel-IAL/Unit-4/January%202014%20(IAL)%20MS%20-%20Unit%204%20Edexcel%20Physics%20A-level.pdf

yep da ii) n iii) one is where i struggled
n note fr ii) in mark scheme da + side is markd on right side so emf should be directed to left right coz current + towards -

Reply 25

How did everyone find it? I thought it was a little bit trickier than last year's paper, and was a bit annoyed that there wasn't a circular motion question.

Reply 26

yeah, quite a few 4/5/6 mark explanations for a change, was slightly harder than last year

Reply 27

Was not the best paper but i expect the grade boundaries to be high (65+ for A*)

Reply 28

Original post by jeremy1999

Was not the best paper but i expect the grade boundaries to be high (65+ for A*)

Looking back at last years' paper it was really quite straight forward (don't know why i messed up a bit last year) and that was 67 for A*. This paper required a lot more in depth knowledge so i hope it will be less than 65 for A* (maybe around 64).

Reply 29

Original post by Qcomber

Looking back at last years' paper it was really quite straight forward (don't know why i messed up a bit last year) and that was 67 for A*. This paper required a lot more in depth knowledge so i hope it will be less than 65 for A* (maybe around 64).

There were a few odd questions (e.g uncertainity about maximum momentum and the flemings LHR) but most were straight forward, just a lot of depth with the 5/6 markers which are not my favourite

Reply 30

what did people put for the 4 marker on the electric field Q with P? and what value for maximum momentum

Reply 31

Original post by milaanpamar

what did people put for the 4 marker on the electric field Q with P? and what value for maximum momentum

That question confused me a bit but talked about a uniform field, and said that E would point towards the negative plate at right angles to it.

Reply 32

Anyone sitting unit 5 also?

Reply 33

How did people find unit 5??

Reply 34

Original post by jeremy1999

How did people find unit 5??

wasn't too bad compared to previous years, minus the space questions!

Reply 35

I thought it was kind of average but i did notice they worded questions a bit differently which did confuse me a bit at times (eg 17a flux question, some of the doppler shift stuff). Overall a decent paper though. Any GB ideas?

Reply 36

wording confused me too so it'll probably be about the same if not ever so slightly higher than last year as it wasnt too bad overall

Reply 37

Original post by milaanpamar

wording confused me too so it'll probably be about the same if not ever so slightly higher than last year as it wasnt too bad overall

Similar GBs to last year would be great! but i reckon it'll be a little higher.

Reply 38

Original post by Qcomber

Similar GBs to last year would be great! but i reckon it'll be a little higher.

Majority of people are retaking in order to achieve A/A* so the grade boundaries should be much higher than usual

Reply 39