AQA Physics PHYA4 - Thursday 11th June 2015 [Exam Discussion Thread]

Ah of course, forgot to mention that

No worries! How's your revision going?


Posted from TSR Mobile

I'm memorizing the unit4 section in the cgp book. So far I've got gravitation, capacitors and magnetic fields. Nothing like having a book in the exam.

You?

By memorising do you mean by rote, word for word, or just revising it until it sticks?


Posted from TSR Mobile

Word for word for the most part. I understand most of it already but I find it helps to know the standard explanations word for word because if you rely on understanding you can miss some details when you try to reconstruct an explanation.

The only ones I don't have word for word are Newton and Coulomb's law of forces and also sections that are specifically devoted to equations such as the little section that covers F=BiL (I only memorized the definition of B there and how to use the formula) and the one right after it that derives the F=BQv formula (easy to derive so didn't memorize)

Oh I see. Kinda forces people to write in prose then!


Posted from TSR Mobile

Yeah, that is the point I think - forces people to demonstrate the language skills we're expected to have. A little weird but not as bad as AQA biology this year (very glad I dropped that after AS) - they have a 25 mark essay question on one paper which is impossible to get full marks in unless you include something relevant that isn't on the specification!

Yeah it's only something like 2-3 marks but it is totally unfair because everything in the essays has to be relevant or they can get marked down. There are two to choose from each year so I guess it's just if you get lucky :/ our college runs a session each week where they can go read articles and stuff together to try and pick up some useful bits but there's no way anyone has time to memorise it all?

There are some where a wordy explanation of the formula will suffice. Especially F=BIL.


Posted from TSR Mobile

Ah right do you think they would make us comment on gravitational fields in the circular motion topic though?

Only think I can envisage is them using the gravitational formula $F=\frac{GMm}{r^2}$ and equating it to the centripetal force for a satellite?


Posted from TSR Mobile

Sounds like I picked the better science

Do you prefer PHYA4 or PHYA5?


Posted from TSR Mobile

True, easy marks those. You just mkae everything =1 in the equation and read it off basically. But you have to remember details such as "right angled to the field". The details come from the context so these aren't hard.

Have you by any chance revised the how exam questions are worded? I tried to build up this system that would allow me to know how to answer specific questions but it got too complicated. One of them was where they ask for "expain so and so with reference to so and so".

Example from AS: Explain the threshold frequency with reference to work function.

I realized that these types of questions are basically asking you to derive the definition of the first thing from the second thing.

In the example we are trying to derive the definition of threshold frequency only using the work function. So first we have to assume that the person we are explaining it to doesn't know what a threshold frequency is, but knows what the work function is. The explanation would go something like this:

The work function is the minimum energy of photons required to remove electrons from the surface of the metal.

The energy of a photon is defined as E=hf. Therefore, if E is less than the work function, it follows (by assumption) that f is too low to remove electrons. So there is a certain frequency below which no electrons are emitted.

Not sure if that makes sense, but I was just wondering if you did any of that type of revision?

Sorry, I think I didn't get notification from this post.

How do you mean if they would ask us to comment?


Posted from TSR Mobile

Probably PHYA5 mostly - I like astro and thermal, nuclear is pretty easy. I'm not so good with magnetic fields half the time! Getting better with the multiple choice section though which is a relief, we're having a MC section test on Thursday to see how our timing is.

Kinda wished the whole syllabus was MC!


Posted from TSR Mobile

The multiple choice section is so annoying though, you get one mark no matter how much work you have to do to get to the answer.

That's true. I like how cheeky some questions are though - others are plain devious.


Posted from TSR Mobile

You basically have to learn a whole new exam technique just for these 25 marks on one paper which takes a while as well :/ I kind of like doing them now - there's something satisfying about knowing you've probably got the right answer (well, or made one of the most likely mistakes!) and being able to guess comes in useful in the actual thing - but the timing and the distribution of marks for that section isn't really right :/