Turn on thread page Beta
    • Thread Starter
    Offline

    3
    ReputationRep:
    Welcome to the WJEC PH1 thread! I noticed there wasn't a thread for this exam, so I'm not sure whether many other people on here are sitting the exam, but for anyone who is: how is preparation going? Any questions about the exam or content?
    Offline

    2
    ReputationRep:
    Hey.

    Preparation is going pretty well but haven't been taught Hooke's Law stuff which is apparently on the syllabus. Have you encountered much of it/is it quite prevalent in past papers?
    • Thread Starter
    Offline

    3
    ReputationRep:
    (Original post by Octan)
    Hey.

    Preparation is going pretty well but haven't been taught Hooke's Law stuff which is apparently on the syllabus. Have you encountered much of it/is it quite prevalent in past papers?
    I looked in the specification. Only one bullet point about Hooke's Law LOL! Poor Robert Hooke.
    It's not particularly prevalent in papers, although sometimes you get springs in parallel/series. Get to know those tricky things in detail because knowing WJEC this year we'll get all kinds of tricks in our exams! Learn about how to add the spring constants in those situations and what happens to total elastic potential etc. For example, you might not have known that addition of spring constants in series is like adding resistances in parallel and vice versa.
    Offline

    2
    ReputationRep:
    (Original post by PrimeLime)
    I looked in the specification. Only one bullet point about Hooke's Law LOL! Poor Robert Hooke.
    It's not particularly prevalent in papers, although sometimes you get springs in parallel/series. Get to know those tricky things in detail because knowing WJEC this year we'll get all kinds of tricks in our exams! Learn about how to add the spring constants in those situations and what happens to total elastic potential etc. For example, you might not have known that addition of spring constants in series is like adding resistances in parallel and vice versa.
    Ah nice, thanks!
    Offline

    2
    ReputationRep:
    Does anyone have a list of the equations we have to know??

    even like the electricity ones etc.
    cheers
    • Thread Starter
    Offline

    3
    ReputationRep:
    (Original post by tsiggers)
    Does anyone have a list of the equations we have to know??

    even like the electricity ones etc.
    cheers
    I don't you need to "know" any.
    http://www.wjec.co.uk/uploads/public...?language_id=1
    Here are all the equations that you will be given. Any other questions you will (hopefully) be able to derive with these equations or otherwise. Hence the key thing is to make sure you completely understand all the equations, and all of the content for that matter.
    Offline

    9
    ReputationRep:
    My revision isn't going too well ):
    Any good revision tips for this paper ?
    • Thread Starter
    Offline

    3
    ReputationRep:
    (Original post by Roxanne18)
    My revision isn't going too well ):
    Any good revision tips for this paper ?
    Anything particular your struggling with? Any concepts that you don't understand? I'll be happy to help.
    Offline

    0
    ReputationRep:
    Hi guys, preparation is going ok for me. I'm usually getting around mid 50s out of 80 for PH1 and I really really want full UMS (mid 60s or higher). Having done most of the past papers I've realised that I always lose marks on the same topics over and over again; projectile motion, electricity, and moments. So if someone could post notes for these topics, or describe these topics then I'd really appreciate it

    thanks a lot for taking the time to read this
    • Thread Starter
    Offline

    3
    ReputationRep:
    (Original post by thegayman)
    Hi guys, preparation is going ok for me. I'm usually getting around mid 50s out of 80 for PH1 and I really really want full UMS (mid 60s or higher). Having done most of the past papers I've realised that I always lose marks on the same topics over and over again; projectile motion, electricity, and moments. So if someone could post notes for these topics, or describe these topics then I'd really appreciate it

    thanks a lot for taking the time to read this
    That's a pretty massive chunk of the module! Maybe narrow it down to some slightly more specific questions so I can help you? Or at least choose one for me to describe, telling me which parts you struggle with within the topic.
    Offline

    0
    ReputationRep:
    (Original post by PrimeLime)
    That's a pretty massive chunk of the module! Maybe narrow it down to some slightly more specific questions so I can help you? Or at least choose one for me to describe, telling me which parts you struggle with within the topic.
    Thanks a lot for replying

    Firstly can you describe how the charge/current/resistance/voltage varies at different parts of a circuit? I always get these calculations wrong

    Also how does the EMF of a cell work

    And finally, what I need to look out for when trying to solve vertical and horizontal XUVAT/projectile motion

    Thanks again
    • Thread Starter
    Offline

    3
    ReputationRep:
    (Original post by thegayman)
    Thanks a lot for replying

    Firstly can you describe how the charge/current/resistance/voltage varies at different parts of a circuit? I always get these calculations wrong

    Also how does the EMF of a cell work

    And finally, what I need to look out for when trying to solve vertical and horizontal XUVAT/projectile motion

    Thanks again
    Before I answer: just a note, be careful about going for full UMS or close in PH1. It's a very different thing to just about getting an A grade or less. To have a realistic chance at full UMS (which is almost always 75/75 on the paper BTW, I've only managed it once due to losing the odd mark here and there on most other papers, and I think PH1 is one of my best modules!),you really need to absolutely UNDERSTAND the physics behind every single concept. I think it would very much help to go over all of your notes and making sure you can explain everything you need to know without doubt. You need to feel that whatever they ask, you'll be able to work it out with your understanding of the physics.

    Now for your questions.Current is the rate of flow of charge. So I'll just explain current, potential difference (voltage, but it's better to call it pd) and resistance in the circuit.Current always splits in parallel. It'll usually split half and half (if two branches) but note that if there are resistors (or any components with resistance in the branches for that matter) then the current splits IN INVERSE PROPORTION with the resistances. This is clear because resistance will resist (obviously) the current. So if you've got 6A going into two branches with 4 Ohms resistance and 8 Ohms resistance, you'll get 4A in the 4 Ohm branch and 2A in the 8 Ohm branch. Because if one branch has double the resistance as the other then it will have half the current. Simple. Current stays the same through all components in series, and make sure you know that this is because of conservation of charge.The total current in the circuit is the current not in branches, i.e. the current 'in series with the cell'.

    Pd is the opposite with voltage being split up in components in series but in parallel it stays the same as it was and no splitting up occurs, the same goes down each branch though. Pd is divided among components in PROPORTION with their resistance (look at a potential divider). The sum of the all the pds in series is equal to the emf of the cell.

    Resistance is added together in series and the 1/totalR=1/R1+1/R2+... rule for parallel resistors. There's not much else really. Oh, and I guess you need to remember that TOTAL RESISTANCE = TOTAL PDS (EMF) / TOTAL CURRENT. I'll post the other answers soon. Any other questions about this topic that I forgot to answer please let me know. Also, any specific past paper questions that you're stuck on I'll help if you want.
    • Thread Starter
    Offline

    3
    ReputationRep:
    EMF of a cell is the electrical energy the cell supplies, converted from its chemical energy, per unit charge passing through the cell. Make sure you learn that definition and UNDERSTAND it, which I guess means that you will automatically have it memorised. That's a great reason to try and understand concepts rather than memorise blindly.

    Note that a cell has a thing called internal resistance, so there is resistance to current inside the cell itself. Therefore energy is dissipated (as heat) in the internal resistance and this energy, per unit charge, we informally call the 'lost volts' (make sure you see why). Hence, by V=IR, and if we call the internal resistance r, the 'lost volts' is clearly Ir.

    So this means, that if volts are 'lost', the pd that the components in the circuit receive is actually less than the emf! This pd will be E-Ir, where E is the emf.
    We call this pd the terminal pd V, so that V=E-Ir (recognise that equation?). The terminal pd is defined as the electrical energy delivered to the external circuit and converted into other forms of energy per unit charge. Understand that too.

    That's pretty much that for emf and the like. You'll be surprised how useful this concept is.
    • Thread Starter
    Offline

    3
    ReputationRep:
    I'll explain projectile motion later. This is actually helping me as well XD.
    Offline

    0
    ReputationRep:
    (Original post by PrimeLime)
    I'll explain projectile motion later. This is actually helping me as well XD.
    You're genuinely a hero, thanks a lot for your help. I'll probably post some more questions on here before the exam so apologies if you feel pestered 😜
    • Thread Starter
    Offline

    3
    ReputationRep:
    (Original post by thegayman)
    You're genuinely a hero, thanks a lot for your help. I'll probably post some more questions on here before the exam so apologies if you feel pestered 😜
    It's fine, that's why I made the thread.
    • Thread Starter
    Offline

    3
    ReputationRep:
    Ok, so projectile motion. There are a few main things to consider; the rest is just use of xuvats. Consider a projectile fired horizontally.
    Firstly, we (almost always) ignore air resistance. This immediately means that the horizontal velocity of a projectile is constant as soon as it is fired. There are no horizontal forces acting on it once it is fired at an intitial velocity u, so it continues to travel at u HORIZONTALLY.

    As for the vertical component, there obviously will always be one (we're not doing space physics here XD). This is because there is a force acting vertically downs on the projectile (weight or gravitational pull of Earth on projectile) and no force acting vertically upwards on it. So there is a resultant force VERTICALLY DOWNWARDS and hence it will ACCELERATE at 9.81ms^-2 (acceleration due to gravity on Earth) vertically downwards.

    So the main difference between horizontal and vertical components is that the vertical is increasing (nonconstant) and the horizontal is constant. Note that this is not always the case, since the projectile may not be being fired horizontally. If a projectile is fired diagonally then you'll probably need to resolve the vector into horizontal and vertical components.

    Remember that THE HORIZONTAL AND VERTICAL COMPONENTS ARE INDEPENDENT OF EACH OTHER.

    So let's now consider throwing a stone upwards. The initial velocity will be the (joint) maximum velocity, as well as the final velocity (the path will be symmetrical either side of the highest point). The stone will travel upwards but will decelerate due to gravity (acceleration of -9.8ms^-2) and will reach 0ms-1 (this is a VERY important point to consider in your xuvat calculations) momentarily at its highest point. It will then continue to accelerate downwards at 9.8ms^-2 and reach another maximum velocity (magnitude, that is. The velocity will clearly be opposite in sign to the initial velocity, since this is the opposite direction) just before it hits the ground.

    Now although these concepts might seem fine, questions in the paper will not always be exactly the same as these examples and you need to be able to adapt your knowledge and understanding to work them out.
    Offline

    0
    ReputationRep:
    (Original post by PrimeLime)
    Ok, so projectile motion. There are a few main things to consider; the rest is just use of xuvats. Consider a projectile fired horizontally.
    Firstly, we (almost always) ignore air resistance. This immediately means that the horizontal velocity of a projectile is constant as soon as it is fired. There are no horizontal forces acting on it once it is fired at an intitial velocity u, so it continues to travel at u HORIZONTALLY.

    As for the vertical component, there obviously will always be one (we're not doing space physics here XD). This is because there is a force acting vertically downs on the projectile (weight or gravitational pull of Earth on projectile) and no force acting vertically upwards on it. So there is a resultant force VERTICALLY DOWNWARDS and hence it will ACCELERATE at 9.81ms^-2 (acceleration due to gravity on Earth) vertically downwards.

    So the main difference between horizontal and vertical components is that the vertical is increasing (nonconstant) and the horizontal is constant. Note that this is not always the case, since the projectile may not be being fired horizontally. If a projectile is fired diagonally then you'll probably need to resolve the vector into horizontal and vertical components.

    Remember that THE HORIZONTAL AND VERTICAL COMPONENTS ARE INDEPENDENT OF EACH OTHER.

    So let's now consider throwing a stone upwards. The initial velocity will be the (joint) maximum velocity, as well as the final velocity (the path will be symmetrical either side of the highest point). The stone will travel upwards but will decelerate due to gravity (acceleration of -9.8ms^-2) and will reach 0ms-1 (this is a VERY important point to consider in your xuvat calculations) momentarily at its highest point. It will then continue to accelerate downwards at 9.8ms^-2 and reach another maximum velocity (magnitude, that is. The velocity will clearly be opposite in sign to the initial velocity, since this is the opposite direction) just before it hits the ground.

    Now although these concepts might seem fine, questions in the paper will not always be exactly the same as these examples and you need to be able to adapt your knowledge and understanding to work them out.
    I wish there was a way of paying you; you're explanation of EMF is so good I actually understand it now instead of memorising it like I did before, and it's better than how they explain in the revision guide. Do you go to a school in England or Wales?
    • Thread Starter
    Offline

    3
    ReputationRep:
    (Original post by thegayman)
    I wish there was a way of paying you; you're explanation of EMF is so good I actually understand it now instead of memorising it like I did before, and it's better than how they explain in the revision guide. Do you go to a school in England or Wales?
    I think there is a way of 'paying' people on TSR.

    Yep, my definitions and all my understanding has come mainly from past papers. My definitions are 'hand-made' as well, so that's why you don't see them in textbooks. I've made them based on understanding rather than memory, so they're easy to apply to other questions as well.

    My aim was to explain all the concepts in such a way that it would all fit together in your brain and make sense, rather than be blindly memorised, so glad that worked. I think I'd do a lot better of a job at teaching people the module than my physics teachers though; most of what I learned had to be self-taught from past papers XD.

    You might have the same revision guide as me, is it the WJEC one? It's pretty good for physics actually, especially for PH2, but as with all revision guides it misses out quite a few details that you can only get from past papers.

    I go to school in Wales (although I'm DEFINITELY not going to uni in Wales).
    Offline

    0
    ReputationRep:
    (Original post by PrimeLime)
    I think there is a way of 'paying' people on TSR.

    Yep, my definitions and all my understanding has come mainly from past papers. My definitions are 'hand-made' as well, so that's why you don't see them in textbooks. I've made them based on understanding rather than memory, so they're easy to apply to other questions as well.

    My aim was to explain all the concepts in such a way that it would all fit together in your brain and make sense, rather than be blindly memorised, so glad that worked. I think I'd do a lot better of a job at teaching people the module than my physics teachers though; most of what I learned had to be self-taught from past papers XD.

    You might have the same revision guide as me, is it the WJEC one? It's pretty good for physics actually, especially for PH2, but as with all revision guides it misses out quite a few details that you can only get from past papers.

    I go to school in Wales (although I'm DEFINITELY not going to uni in Wales).
    I just did jan 2013 and got 72/80 which is full UMS according to the wjec website so thanks slot for your help.

    One question I did lose most my marks on was question 6, where I lost 5 marks. Could you explain the proportionality ideas in the resistivity equation?, ie as a variable increases which variables increase/decrease

    Thanks
 
 
 

1,075

students online now

800,000+

Exam discussions

Find your exam discussion here

Poll
Should universities take a stronger line on drugs?

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

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.