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AQA Physics Unit 1 PHYA1 20th May 2013

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you are correct. I've seen this in many past papers

the mass of electrons is negligable, you never include it

Yeah I was almost certain about that. I've dropped enough marks on electricity as it is, Lord knows I can't afford any stupid mistakes.

Reply 941

zedd01

What was your answer to the last question, was it 74000 ohms?

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Reply 942

Maloneyyy

What did everyone put to show that the circuit conserved energy?
I put that the overall power of the circuit was 50.2W or something like that and then i took away all of the work done by the resistors and got a negative answer?

Reply 943

samueliscool

Original post by lebron_23

As did I. Not entirely sure what the other poster means, but I did the sameas you. Charge was +3.2x10^6. We could, of course, be wrong..

Electricity was killer though.. Probably dropped most of the marks available there :redface:

Any idea if there will be a mark scheme up for this, similar to how they do it for maths?

Sounds like you and I are in exactly the same boat, I reckon at best I've got 8/21 on the electricity part, hoping that I didn't drop more than 3 or 4 on the rest and can scrape an A!

Reply 944

lebron_23

Original post by SamHedges

What happens when intensity's constant and frequency decreases? I put rate of emission decreases until fmin.

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That's what wave theory would say, but if the frequency were to remain above the threshold frequency, surely the emission of electrons wouldn't be affected at all? I mean, the only thing that ever changes anything is the intensity, and it only changes the rate of emission at that.

Reply 945

Monster94

Original post by zedd01

What was your answer to the last question, was it 74000 ohms?

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I got that. :smile:

Reply 946

Redflame

I've just realised that I made a pretty silly mistake and mistook the ion for a negative one and put a minus sign in front of the specific charge Will I lose marks for this?

Reply 947

Mr. T. Face

Original post by zedd01

What was your answer to the last question, was it 74000 ohms?

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Um, no, (6/10000+x)*5000=0.75, so x = 30000 Ohms

Reply 948

KES4lyf

My answers to the numerical questions, in order of how they were in the paper, not guaranteed to be right but just.. yeah yolo

20 protons

28 neutrons

18 electrons

3.2 x 10^-19

4.2 x 10^6

1.8

4.4

128

10.

45 v

11.

100 HZ

12.

6.3

13.

5.7

14.

2.85

15.

1.35

16.

4.2

17.

2.9

18.

26.46 W

19.

16.245 W

20.

7.695 W

21.

50.4 W

22.

6.7 x 10^-5

23.

0.33

24.

3 x 10^4 ohms

also 16V as the division for Y, and 2ms for the time base per division

(edited 10 years ago)

Reply 949

Substitution

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they asked for the ion, I did

2x.6x10'-19 / (mass of protons neurons and electrons) is this wrong

Reply 950

Thecookieman

Anybody know of an unofficial mark scheme going up? :smile:

)

Reply 951

lebron_23

Original post by samueliscool

Sounds like you and I are in exactly the same boat, I reckon at best I've got 8/21 on the electricity part, hoping that I didn't drop more than 3 or 4 on the rest and can scrape an A!

Yeah, exact same situation here. I really really hope that I didn't do anything stupid in the rest of the paper. Thinking I may have lost a mark on the 6 marker as I only gave one similarity, and then lost at least 15 on the electricity.

I'm anxious to know what people put for the question regarding internal resistance. Question 6 I believe it was.

Reply 952

Tit

I changed 2 of my charge calculations from + to -! Would I lose marks for this? I'm an idiot I know!

Reply 953

Tuya

Original post by Redflame

I've just realised that I made a pretty silly mistake and mistook the ion for a negative one and put a minus sign in front of the specific charge Will I lose marks for this?

Probably 2 marks if you carried that negative to the next part, I almost did exactly that, but I found out when I checked for the second time :smile:

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Reply 954

Xiomara

For the last one, was it 6-1.5V, so the variable resistor had 4.5 V over it, then you divided that by the current to get the resistance?

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Reply 955

posthumus

I got stuck by far on the first one :confused:

after numerous crossing out... I went for 18 x 1.6x10^-19 because when the atom is neutral you don't do 0/mass

And it was only 1 mark, so I just thought it had to be that :/

So confused though still