Ocr a2 8 June exploring physics paper 2 8th June 2018 unofficial markscheme

Reply 60

TheYearNiner

21

Glad I took biology over physics looool

Reply 61

Bulletzone

OP

22

OMG i added my first ever poll :woo:

(edited 5 years ago)

Reply 62

omarathon

13

Original post by uponthyhorse

Points for improving Planck's constant experiment? I got that you need to look at led in dark room through a tube to have more accurate V_0 and that graph should go through origin to indicate direct proportionality, but didn't really know what else or the kind of errors it would imply

There was scatter. Reduce random errors by taking many readings and average.

Reply 63

Jadejay

8

I always regret coming here :frown:

come out of the exam feeling I did alright then come here and realise how many stupid mistakes I made T_T

Reply 64

EmilyKellett

6

Original post by Bulbasaur10

Was 1.46V for the emf?

Ooh yeah now you say it I think it was

Reply 65

uponthyhorse

15

Original post by omarathon

There was scatter. Reduce random errors by taking many readings and average.

Whoops forgot the obvious points. Will need to remember that for the synoptic paper :biggrin:

Reply 66

EmilyKellett

6

Original post by uponthyhorse

Points for improving Planck's constant experiment? I got that you need to look at led in dark room through a tube to have more accurate V_0 and that graph should go through origin to indicate direct proportionality, but didn't really know what else or the kind of errors it would imply

Thats the only error I could spot too. It was 4 marks so hoping what I wrote got me 2

Reply 67

Bshoulder13

2

What value didn’t anyone get for calculating plancks constant and the percentage difference?

Reply 68

Bulbasaur10

12

Original post by EmilyKellett

Ooh yeah now you say it I think it was

Phew because nobody at my school could remember! I hope we're right! :h:

Reply 69

zeldor711

18

Original post by Bulletzone

Or maybe I did put C :confused:

But we can all agree the resistance (effective) was 25 ohms 😋

Haha yep, that we can

Reply 70

omarathon

13

Original post by uponthyhorse

Whoops forgot the obvious points. Will need to remember that for the synoptic paper :biggrin:

Haha yes I hate missing easy ones. I wrote so much in the gold leaf electroscope question but didn’t say it was the photoelectric effect :biggrin:

Reply 71

uponthyhorse

15

Original post by Bulbasaur10

Phew because nobody at my school could remember! I hope we're right! :h:

I think would be dependent on the gradient you drew but I got between 1 and 2V so it sounds about right

Original post by Bshoulder13

What value didn’t anyone get for calculating plancks constant and the percentage difference?

got 6.4 × 10^-34 and ~4%

Reply 72

Bulbasaur10

12

Original post by omarathon

Haha yes I hate missing easy ones. I wrote so much in the gold leaf electroscope question but didn’t say it was the photoelectric effect :biggrin:

If you mentioned photoelectrons surely you will get the marks? It just didn't seem to fit in with my answer stating right at the start 'this is an example of the photoelectric effect.' Plus I was already wasting too much time and I'm sure a lot of people were too. :biggrin:

Reply 73

EmilyKellett

6

Original post by Bshoulder13

What value didn’t anyone get for calculating plancks constant and the percentage difference?

I can’t remember what value i got, but I know my percentage accuracy was 4.1%

Reply 74

benmorris6

5

I think I got the capacitance to be 1.18x10-8...?

Also, have seen a few people saying “emf = 1.46V”

I don’t remember calculating emf at all. Did I miss a question?

Reply 75

uponthyhorse

15

Original post by omarathon

Haha yes I hate missing easy ones. I wrote so much in the gold leaf electroscope question but didn’t say it was the photoelectric effect :biggrin:

Lool I don't remember writing that either described it in quite some length tho

Reply 76

Isopher

4

Original post by Jadejay

For the sketch of the graph was it half the amplitude and double frequency?

No the amplitude stays same I think as magnetic flux has to stay constant.

Reply 77

Edamcheese123

4

Original post by uponthyhorse

Points for improving Planck's constant experiment? I got that you need to look at led in dark room through a tube to have more accurate V_0 and that graph should go through origin to indicate direct proportionality, but didn't really know what else or the kind of errors it would imply