A-Level Physics: Explaining Resistance to a 15-Year-Old

[Lokolo]

Has anyone here done A-Level physics? I want to know what its like so please say! by the way this is an English qualification so if you are all americans you may not understand what I am on about!

BUT, I need some help in explaining how increasing a length of wire will change resistance (with a set current and voltage) but could you make it simple enough for me to understand and explain it so I can make sure I know it and not just copy it! (I am 15 by the way!)

Thanks all!
Lokolo

 

[Duncan]

Hi Lokolo,

I took A level physics about 10 years ago(blimey I am old). From what I remember, much may have changed in 10 years including my memory, I did quite like it. There were quite a lot of equations to learn, but they were all quite simple. For instance

R = ρl/A

R = Resistance in ohms
ρ = resitivity in ohms per metre(note units, very important in sciences)
l = length in metres
A = cross sectional area of conductor

It's a simple formula for the resistance of a length of wire.
Go to this website for more info: http://regentsprep.org/Regents/physics/phys03/bresist/default.htm

I would explain more but I have a train to catch. Good luck with your choices.
I would recommend Maths A level for obvious reasons.

Duncan.

 

[Lokolo]

thanks, yeh don't worry I will be doing Maths as well, as long as I get my GCSE's. The sight was useful thanks for that!

Lokolo

 

[Cheman]

Basically, think of it like resistors - if you put more resistors in series you increase the difficulty for the electrons to pass through since more collisions, therefore increased resistance. Its the exact same pricipal when you increase the langth of a wire. :-) Hope this helps.

 

[Claire84]

Hey, I'm in level one at uni doing Maths and Physics so it wasn't agessss ago that I did my A level Physics. Things haven't changed that much fro what Duncan has said, and the majority of eqts are given on the data formulae sheet (the main ones anyway, in our case). It's definitely one of the harder A levels, but it is interesting. Have a look at the syllabus first before you make any choices, if it's available to you. We got to do medical Physics for AS level and it was the best part of the course for me.

 

[jcsd]

Make sure you do take pure maths as well otherwise you will struggle. Mechanics will also be an advantage.

 

[Claire84]

I think if you take Maths A level you have to do both pure and mechanics. With ours we did 3 pure modules, 2 mechincs modules and one stats module, although I know this differs depending on which board you go off and which school you're at.

 

[Claire84]

Btw, if there are any typos in my posts just ignore them- am currently under the influence!

 

[jcsd]

I think if you take Maths A level you have to do both pure and mechanics. With ours we did 3 pure modules, 2 mechincs modules and one stats module, although I know this differs depending on which board you go off and which school you're at.

I did my A-levels 6 years ago, but when I did maths there were four AS levels which could be combined to make 2 A levels, and it was optional which ASs you took, though it was generally accpetd that for amaths A-level you took Pure and Statistics.

 

[jcsd]

Don't worry about typos, my posts are always riddled with them and I very rarely have the excuse of being under the influence.

 

[Claire84]

Ah right, for our AS level we did 3 modules, and for A2 we did 3 modules, which is what we got our A level out of. I didn't know AS levels had been on the go for 6 years though. I'm such a numpty!

 

[NC1987]

I'm not doing A level Maths

New member here!

You say you need a level maths to do physics or you'll struggle.

I'm doing physics but not maths, and i got an A for AS module 1 and hoping for the same for other modules ( i hope). I never needed any of the advanced maths stuff.

Is it going to get harder for A2? I heard about differentiation (that funny f thing)

 

[Claire84]

It probably depends on what topics you're taking next year. Have you done mechanics yet or are you still to do that? I mean doing maths would help but it does depend on your syllabus and your ability to pick stuff up quickly. The people who didn't do Maths A/AS level in our Physics class struggled a little more, but I think that was more to do with their overall ability as opposed to anything else (not being mean to them here, just staing the facts). As long as you'e confident with your Physics and maybe prepared to work a little harder when something like differentiation comes up, you'll be okay. It'll be at a lower level than A level Maths so you'll be fine. You're oviously good at Physics so I wouldn't be too worried. Well, that's just my humble opinion anyway!

 

[Lokolo]

Well I am thinking of doing Chemistry, Physics, Maths and Computing for A-Levels. I am doing my GCSE's at the moment (doing the exams Jul 05): French, Eng Lit, Eng Lan, Maths, Electronics, Business Studies, Music, Chemistry, Physics and Biology. As long as I get the grades I should do the A-Levels that I want to do.

Lokolo

 

[rattis]

I am currently finishing my first year of an A-level in physics. (Previous posters have outlined the course content well.) I have also taken Computing, Maths and Further Maths this year. Next year I will take A2 Physics, A2maths and A2 further maths, and AS electronics.

I would recommend that you do the PPM (first year - pure 1 and 2, mechanics 1. Second year - pure 3 and 4, mechanics 2) if avaliable. If you really want to do continue physics to a further stage, i.e. university degree, then furthur maths will be good, but this can be picked up as an AS level in your second year. A2 maths is need for a physics degree.

Computing should not be too hard as you are doing maths and physics, it is extremely easy if you are doing GCSE ICT or likewise course. I must warn you that the computing course is very theroy based, and you will probably not do a lot of work on the computers apart from a database project and some basic programming.

How fun or boring you find the course will depend on the teacher(s) you get and the other people in your classes. If you have a genuine interest (which you must have to have come here) then you will do well in the subject as long as you attend.

Any questions?

 

[Fuego]

I just finished my Physics A-level. Out of the five A-levels i did, physics was the most interesting after maths. A lot of it is just building on the stuff you do at GCSE (mechanics, waves, electricity etc), but some of the new stuff is very interesting (radioactivity, thermodynamics, quantum phenomena). Its not a difficult A-level. If you know all the formulas and principles its no problem. Chemistry is much more difficult A-level IMO.

A-level maths will help you with A-level physics (especially if you do some mechanics modules), but its not essential. To be honest, the maths content of physics A-level is pathetic. All you really need is GCSE trig and quadratic equations. You occasionally have to do a bit of algebra and manipulation of the formulae, but if you get a decent GCSE maths grade it shouldn't be a problem.

The only time when you really have to think mathematically about anything in physics A-level is in the synoptic module, where you have to be able to derive some simple equations.

An understanding of A-level calculus will help you see where some of the equations come from, but you don't actually need to know that. You just need the end results.

If you think you may want to do a physics degree in the future, A-level maths is essential. There are no unis (not in the uk anyway) that will offer you physics courses unless you have maths A-level.