OCR Physics B A2 synoptic pre-release discussion

Yeah, those are just set out by random physics teachers who disregard the importance of success statistics for the government, the paper will be easier then that. I don't think P=Fv was even on the course so only those that did Mechanics2 would be able to do that.

Reply 63

i agree, those questions are thought provoking but a lot of it probably wont come up in the OCR exam.

Thanks though for the equation for the first question, ive never actually come across that one before... odd... but if its not on syllabus then why would i? :P

Reply 64

Also.. as Entropy isnt really covered on the course properly ive only looked at it briefly as a majority of my class do chem/bio to :frown:

Would someone be able to give a brief and simple definition of Entropy, i know WHAT it is, just how do you apply it and what equations etc will i use? Ive read through the booklet i have but im more of a practical and logical person and can't visualize it all properly if its a large block of text :frown:

Any help would be appreciated

Reply 65

We won't be expected to know anything more than what is on that booklet for entropy. They've given us the one equation too. I just remember the booklet definition as 'the measure of disorder present in a system' which I think is about as simple as it gets really. That diagram with the box of oxygen and nitrogen molecules sums it up quite well too, since there are more possibilities for the molecules to be arranged differently in a greater area, B has a greater entropy to A.

Reply 66

is there any answers to the document somone psoted before? ive had a go at some of the Q's but want to check them to see if im right.

Nope, no answers.

Just a quick and slightly stupid question:
We still have the formula book for this exam right?
Haha i think nerves are getting the better of me :biggrin:

Reply 69

ironfarm

Yes, we have the formula booklet and a fresh copy of the pre-release material. It says so on the third bullet point on the pre-release material.

Reply 70

eguk

just a stupid question.. what is pressure? isnt density: mass/volume? but i keep getting confused between the two

Reply 71

Pressure: the force applied to a unit area of surface

density: The density of a material is its weight for a given volume.

Reply 72

ive been revising ALL day (with breaks) and feel i havent covered too much :s-smilie:

What topics are you all looking over?
Ive got that list that was on page 1 (or 2) with stuff to revise and had a look over that but is anyone else looking at additional stuff..

eg. im also looking at Bits/Bytes stuff again from AS as that is kinda like entropy with its manny many different combinations of bits etc... (it was on the Question sheets listed earlier in the thread)

Some of you have mentioned refractive indexes, i take it this would be for section B?
Im jsut a bit worried im not covering the right stuff... especially for section B

Reply 73

I planned on going through every single chapter revision guide (provided on CD). I got distracted yesterday and only did 3 but I stormed through them today and I'm on my last two. Once I do these I'm going to hit the past papers (doing section B's only) I think. I'll take a look through the questions from 'the teachers forum' but I won't spend too long on them.

From the impression I have, we should be revising everything but paying meticulous attention to stuff like Bolztmann facotr and stuff so that we really understand that stuff.

whats flux linkage?

And can someone explain the signifiance of blunt drills producing more caloric? Why does this differ from what a sharp drill would do? Friction im guessing, but dont want to be taking any risks...

Reply 76

mikejones

Tazman123

I planned on going through every single chapter revision guide (provided on CD). I got distracted yesterday and only did 3 but I stormed through them today and I'm on my last two. Once I do these I'm going to hit the past papers (doing section B's only) I think. I'll take a look through the questions from 'the teachers forum' but I won't spend too long on them.

From the impression I have, we should be revising everything but paying meticulous attention to stuff like Bolztmann facotr and stuff so that we really understand that stuff.

all 18 guides???

Reply 77

datr

12

Flux linkage is the number of coils times the flux passing through them I think.

\displaystyle \epsilon = -\frac{dn\phi}{dt}

Flux Linkage =

\displaystyle n\phi

Reply 78