Good luck for physics!

[Alwin]

Good luck with physics guys!

Just a few tips for tomorrow in case your stressing about tomorrow:

• GOOD PHYSICS IS ALWAYS REWARDED
• Take a look at the 2013 physics teachers conference, there's a bunch of useful stuff on there http://www.vicphysics.org/conf2013.html
• Know your detail study well so you can smash out the multiple choice (personally I recommend this first, but it's up to you)
• I just got back from helping my mate with physics, and no offence to him, but make sure you can explain Lenz' Law in the relevant context. A generic response: the induced current will oppose the magnetic field that caused the current will not cut it. Refer to what direction the external magnetic field is, increasing or decreasing, refer to magnetic poles if you wish, THEN state Lenz' Law and the right hand grip rule or slap rule you used to determine the direction the current. 3marks.
• For calculations, use subscripts!_subscripts! It makes it a lot easier if your dealing with lots of the same thing, such as v_initial, v_final, and just v in general.
• Make sure you use correct and appropriate SI units. Just a word on units in the box, you are allowed to cross this unit out and write your own if the question doesn't specify for a specific one. For example, if it asked for MeV and you found energy in terms of donuts Homer eats on average per Simpsons episode you don't get a mark for the final answer
• And show working!!! You get full marks if you just write the answer in the box, but why take the risk? If you show working, then if you get the final answer wrong you can still get partial marks! You don't need to write out the formula explicitly, examiners will just do check to make sure you made a reasonable substitution and award a partial mark
• Consequentials... don't rely on them but they are there, just telling you. BUT according to my teacher last year if there is an alteriror method that doesn't rely on a previous part and you use an incorrect number, you get no marks. Eg the motion question where in part a) they ask for the time taken, and in part b) asks for distance and you can use a different formula without time, you cannot blame an incorrect a) for getting b) wrong.
• Make sure your diagrams are neat and labelled. Occasionally they award marks, if it's in an explanation question
• Just a word on explanation questions, ALWAYS link back to relevant physics concepts or formulas AND refer to the context of the question. Generic explanations from your cheat sheet will rarely suffice for full marks, partial at best.
• Sig fig and decimals are not accessed like in chemistry, just give them to a reasonable number - don't show off your calculator's functions. Most can go to 10dp... I don't think examiners want to know that by marking answers with 10dp
• And know your unit conversions too, km/h -> m/s, J -> eV etc etc
  
• As for cheat sheets... gosh there's so much I could say about this but I'd really recommend a personalised one and not a generic one you found off the internet. That said, I will be uploading my ones from last year as soon as I find them haha + some other resources people were asking for
• Oh, and er one last thing. GOOD LUCK AND EVERYONE JUST DO YOUR BEST

PS: My next exam is next week thursday so I'll try to answer everyone's qs on this board unless someone gets to it first, but if you have a really desperate question then post it here and I'll defs answer

PPS: I was looking for this yesterday but couldn't find it (turns out it was saved on my laptop lawl). Attached since it's small enough, is just a motion sample test thingy I did ages ago... enjoy haha

PPPS: Found most of my old cheat sheets, sorry for low quality

Unit 3

Unit 4

[CossieG]

Thanks man!

Could you give me a nice definition of slip rings for my summary sheet?

[Alwin]

Thanks man!

Could you give me a nice definition of slip rings for my summary sheet?

A bit verbose, but here:

Slip rings are used primarily in AC generators (AC motors aren't in the course iirc)
As the coil rotates through the magnetic field, it experience a varying flux. When parallel to the field, the armature experience zero flux, but as it rotates the magnetic flux changes and a current is induced according to Lenz' Law. But as the armature passes the perpendicular point induced current flows in the opposite direction. Slips rings are used to ensure the ends of the armature are connected to the same terminals thus the sign of the terminals change every half turn generating an AC output.
Slip rings are also used instead of conventional wires because these wires would become quickly tangled.

Ofc if this was in a question with a diagram you would make relevant reference to the side AB of the coil etc etc Hope this is what you were looking for!

[lzxnl]

Good luck with physics guys!

Just a few tips for tomorrow in case your stressing about tomorrow:

• GOOD PHYSICS IS ALWAYS REWARDED
• Take a look at the 2013 physics teachers conference, there's a bunch of useful stuff on there http://www.vicphysics.org/conf2013.html
• Know your detail study well so you can smash out the multiple choice (personally I recommend this first, but it's up to you)
• I just got back from helping my mate with physics, and no offence to him, but make sure you can explain Lenz' Law in the relevant context. A generic response: the induced current will oppose the magnetic field that caused the current will not cut it. Refer to what direction the external magnetic field is, increasing or decreasing, refer to magnetic poles if you wish, THEN state Lenz' Law and the right hand grip rule or slap rule you used to determine the direction the current. 3marks.
• For calculations, use subscripts!_subscripts! It makes it a lot easier if your dealing with lots of the same thing, such as v_initial, v_final, and just v in general.
• Make sure you use correct and appropriate SI units. Just a word on units in the box, you are allowed to cross this unit out and write your own if the question doesn't specify for a specific one. For example, if it asked for MeV and you found energy in terms of donuts Homer eats on average per Simpsons episode you don't get a mark for the final answer
• And show working!!! You get full marks if you just write the answer in the box, but why take the risk? If you show working, then if you get the final answer wrong you can still get partial marks! You don't need to write out the formula explicitly, examiners will just do check to make sure you made a reasonable substitution and award a partial mark
• Consequentials... don't rely on them but they are there, just telling you. BUT according to my teacher last year if there is an alteriror method that doesn't rely on a previous part and you use an incorrect number, you get no marks. Eg the motion question where in part a) they ask for the time taken, and in part b) asks for distance and you can use a different formula without time, you cannot blame an incorrect a) for getting b) wrong.
• Make sure your diagrams are neat and labelled. Occasionally they award marks, if it's in an explanation question
• Just a word on explanation questions, ALWAYS link back to relevant physics concepts or formulas AND refer to the context of the question. Generic explanations from your cheat sheet will rarely suffice for full marks, partial at best.
• Sig fig and decimals are not accessed like in chemistry, just give them to a reasonable number - don't show off your calculator's functions. Most can go to 10dp... I don't think examiners want to know that by marking answers with 10dp
• And know your unit conversions too, km/h -> m/s, J -> eV etc etc
  
• As for cheat sheets... gosh there's so much I could say about this but I'd really recommend a personalised one and not a generic one you found off the internet. That said, I will be uploading my ones from last year as soon as I find them haha + some other resources people were asking for
• Oh, and er one last thing. GOOD LUCK AND EVERYONE JUST DO YOUR BEST

PS: My next exam is next week thursday so I'll try to answer everyone's qs on this board unless someone gets to it first, but if you have a really desperate question then post it here and I'll defs answer

PPS: I was looking for this yesterday but couldn't find it (turns out it was saved on my laptop lawl). Attached since it's small enough, is just a motion sample test thingy I did ages ago... enjoy haha

I was just about to wonder...huh...no exam for you tomorrow...then I realised. Oh wait.

[Alwin]

Found my old cheat sheets

here: http://imgur.com/a/wNYno#0