EDEXCEL A2 Physics EXAM Unit 4 Physics On The Move 20th June 2016 (NOT I-A-L)

**** i got 83% for percentage decrease in charge

i changed the multiple choice sphere charge question at the last second. I circled double both charges because i remember doing a past paper question where one of the charges was halved but angle of point charge remained the same. Therefore had no effect on the force. Had to be both

nope its definitely halve just one man

I put higher value...

For multiple choice was it 0.37 or 0.63? I think I may have misread question.

it was 0.37

Yay that's what I got . And is it 17% or 33%? There is so much confusion.

For multiple choice was it 0.37 or 0.63? I think I may have misread question.

0.37, it said "remaining charge".

An good thought it said the opposite. Was 0.024 an answer as well?

For the question about the magnetic accelerating upwards away from the coil. When the questionasked you why the magnitude of current changes. Did you say it increased because rate of change of flux linkage increases since speed is increasing. Or it decreased as B decreases since the magnet is moving away


Posted from TSR Mobile

For the question about the magnetic accelerating upwards away from the coil. When the questionasked you why the magnitude of current changes. Did you say it increased because rate of change of flux linkage increases since speed is increasing. Or it decreased as B decreases since the magnet is moving away


Posted from TSR Mobile

I talked about the rate of change of flux linkage increasing as it was accelerating upwards, so Faraday's law states the induced emf increases and so does the current -- is that similar to what you wrote?

I think it's time for me to stop worrying about unit 4 and concentrate on S2/FP3/Unit 5 just two more days of exams

Unit 5 is in one week, not two more days

Yeah that's what I wrote but a few people in my class said flux density decreases as the magnet moves away so flux linkage decreases and so current decreases


Posted from TSR Mobile

You are correct if the question implicitly says starting from the initial position
but the question as I remembered, was
it says it can be the allowed difference of silicon from its position is 0.7 mm
meaning +/- 0.7 mm from the position is all possible i.e Maximum possible d is 3.5+0.7 minimum possible d is 3.5-0.7
hence Dmax=4.2 mm
Dmin=2.8 mm
Question ask the maximum possible allowed percentage decrease
so as maximum possible d is 4.2
minimum possible d is 2.8
the maximum possible allowed decrease is from 4.2 mm
to 2.8 mm as
it could be at 4.2 but is at 2.8
hence max percentage decrease is 33.3%

nevertheless I actually do understand your point , it is valid and logical from your prospective but

but this does not mean that you start from 3.5