EDEXCEL - Physics Module 2

Scroll to see replies

errr no...(i'm not trying to be rude or anything)

but have you not looked it up in your text-book or something? e heat engine and a heat pump are kind of opposites...look it up...there is now way a heat engine and a heat pump are the same thing!!!

anyone else care to correct us?

Reply 41

username51312

Kennychan222

My version:

1) Voltage (potential difference), Voltage, Current, Charge

i think this one was current too
it said rate of change and current is a rate of change of charge

Reply 42

Kennychan222

UAG

i think this one was current too
it said rate of change and current is a rate of change of charge

It said SI base unit, not the complex unit in the last part of question

Reply 43

</gibberish>

Heat pump = Cold --> Hot, work is done to facilitate this movement of energy, and as someone correctly stated - this is the opposite of a heat engine.

http://en.wikipedia.org/wiki/Heat_pump

Dont talk crap before you know its true, you will just make people worry!

Reply 44

Kennychan222

Noizuf

UAG is right. It's current.

3rd part is current (Concerning about rate of charge)

4nd part is charge (SI single unit)

Reply 45

</gibberish>

Kennychan222

3rd part is current (Concerning about rate of charge)

4nd part is charge (SI single unit)

Its current, current is the SI base unit.
http://physics.nist.gov/cuu/Units/units.html

Stop posting rubbish!

It is explicitly stated that charge is a derived quantity.

Rubbish

Current is the base quantity, charge is a derived quantity; there are only 7 base quanitities anyway; its in the NAS book if anyone wants to read it. (NAS Unit 1 book)

Reply 48

seanthebean50

On the heater question, the resistance of the single strips was 22.5 ohms

the total resistance was 4.5 ohms and it is a parallel combination,

so 1/Rtotal = 1/R + 1/R + 1/R + 1/R + 1/R
1/Rtotal = 5/R
1/4.5 = 5/R
R = 5 x 4.5 = 22.5

Reply 49

</gibberish>

Finally someone who got something right^^ lol

Reply 50

luxie_luxington_

seanthebean50

That seems familiar, what did you write in the question that asked what would increase the power? I put having more strips of wire in parallel so the total resistance would go down, hence higher current.. hence higher power... is that correct?!

Reply 51

michaelyus

That thermodynamics question I got everything wrong: yet I understood it so well (I almost ran out of time, and rushed that bit...and got everything wrong). That heat engine or pump question, I didn't really understand it.
Electricity was fine for me, apart from that "how to increase the power" of the heater "without changing dimensions or voltage".

That first question was voltage, voltage, current, ampere, wasn't it?

Reply 52

Notnek

michaelyus

That first question was voltage, voltage, current, ampere, wasn't it?

Was ampere one of the options?? I put current for the last one. If ampere was an option, I got it wrong.

Reply 53

Dr.A

the exam was good in general well actualy i think its the best exam i did..
1st Question was
-Potential Difference
-Potential Differnce
- the 3rd and the 4th i cant remember current and sth else i think Ohm ?! i cant remeber

Reply 54

Kennychan222

So I got wrong on the last part of question...I may lost 5 marks from unit 2 at least.....7-8 marks from Unit 1....>_<

Reply 55

</gibberish>

Yeah 4 lost volts inside the cell therefore 8 are to be found externally (12 volt supply), current is constant in a series circuit therefore 8v/4ohms = 2A.
You couldnt use the r value yet because it was worked out afterwards, if you had of it would still be 4 volts/2 ohms = 2 A

Reply 56

</gibberish>

I think so, current was worked out first so aslong as you used all the right equations in the following questions using YOUR value for current, it should be fine.