You are Here: Home >< Physics

# AQA Physics PHYA4 - 20th June 2016 [Exam Discussion Thread] watch

1. (Original post by Mango Milkshake)
1st one

area under graph
Couldn't you just calculcate Energy for first capacitor, then energy for when it decreases, then minus biggest from smallesT?
2. MCQ's were harder. Paper was okay. I think boundaries will be a bit higher than last years. Maybe 52 A, 47 B, 42 C?
3. (Original post by Burnzi)
How did you guys work out the time constant of the capacitor? I worked out the resistance then used that to get the time constant but then the next part of the question asked you to work out the resistance so I'm guessing you were supposed to do the first part a different way
yes, you use decay of charge equation with voltage
(Original post by TheLazyGuy1)
it is Y to X because the magnitude was -2F
magnitude can't be negative lol
4. Was potential 5Q/8piEor and was the other potential -4GM/d?

Posted from TSR Mobile
5. For the multiple choice with 2nc and -1nc you added 2nc to both didnt you? So it would repel by 4F? I wasn't so confident
6. 1/g my friend. Not g

Posted from TSR Mobile
7. (Original post by Mango Milkshake)
Daughter
No
8. (Original post by Hattie28)
I got 6.06x10^6 for something aswell
yessss i got 6.06x106 aswell as g would be 4x greater
9. (Original post by lucabrasi98)
How can you guys have found the 6 marker hard? Haven't your teachers made you do past ISA's? Because I'm pretty sure I've basically seen that exact question in an ISA
We did this this year.
10. (Original post by lucabrasi98)
How can you guys have found the 6 marker hard? Haven't your teachers made you do past ISA's? Because I'm pretty sure I've basically seen that exact question in an ISA
I thought that was the easiest 6 marker of any past papers simply because I've done the experiment before but I'd think that if you haven't done it it would be very hard.
11. MC was definitely more difficult.. Required many more calculations and had more little trip-up questions. On the other hand second B was pretty standard with only application/HSW questions posing much difficulty. I would expect grade boundaries to be average.
Also boundaries will no doubt be marginally lower due to the silly people completely missing the question over the 6 marker so we all have to thank the silly people in question

Posted from TSR Mobile
12. (Original post by duncant)
what did people say for the effect when that guy recorded only half of T? was it (1/4)g?
I said the g (calculated in his investigation) is 4 times greater than what it should be as
T=2π x √(l/g)
T^(2)=4π^(2) x (l/g)
g=(4π^(2) x l ) / T^2

Therefore g is proportional to (1/T^2)

0.5 x 0.5 = 0.25
1/0.25 = 4 (Hence the effect results in the g calculated being 4 times greater than it should be.)

A little long-winded I know but I hope it makes sense.
13. (Original post by TJ_gym)
Couldn't you just calculcate Energy for first capacitor, then energy for when it decreases, then minus biggest from smallesT?
That's what I did. Plus the graph wasn't even starting from 0. Finding the area would be dodgy
14. (Original post by Yo12345)
Was potential 5Q/8piEor and was the other potential -4GM/d?

Posted from TSR Mobile
I put -5Q, for the first one, was there a positive version?

I also put -4 for the second one.
15. (Original post by rich1334)
For the multiple choice with 2nc and -1nc you added 2nc to both didnt you? So it would repel by 4F? I wasn't so confident
Thats what i put but like 5 people below this have said otherwise
16. Can someone put the marks for each question for section B?

Posted from TSR Mobile
17. (Original post by Mango Milkshake)
no

i put the amplitude has to be lower than 10 degrees
18. (Original post by Mango Milkshake)
yes, you use decay of charge equation with voltage

magnitude can't be negative lol

It asked for the direction of the force on x which was indeed y to x
19. Ergh I done my graph like this, anyone else done it like this -_-
Attached Images

20. (Original post by james2mid)
No
(Original post by james2mid)
No
It clearly said recoiling nucleus.

if its recoiling it mustve already emitted the alpha

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: January 9, 2017
Today on TSR

### The most controversial member on TSR?

Who do you think it is...

### Uni strikes! How do they affect you?

Discussions on TSR

• Latest
Poll
Useful resources

Can you help? Study help unanswered threadsStudy Help rules and posting guidelinesLaTex guide for writing equations on TSR

## Groups associated with this forum:

View associated groups
Discussions on TSR

• Latest

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE