[supaabzz]

Cant see any threads about this.

So yeah.. Hows revision going on? Its easy to lose marks on this paper. Ive done January 2012 paper as mock and got 40/60, lost stupid marks.

[KoalaKim]

(Original post by supaabzz)
Cant see any threads about this.

So yeah.. Hows revision going on? Its easy to lose marks on this paper. Ive done January 2012 paper as mock and got 40/60, lost stupid marks.

I know exactly what you mean!!! The only good thing is that the grade boundaries are normally quite low much lower than chem A anyway!!!

[hihihihihi]

Im retaking G491 been getting around 45/60 in most papers. done about 12 past papers

[hihihihihi]

btw do you have the paper you can scan and post or upload? Can't find it anywhere online.

[FreddieKeen]

I'm pretty good at G491 and I will try to help any queries anyone may have (it is good for everyone if you post queries).

There hasn't been a lot of discussion here yet so here are some questions for you to get thinking about:

1) What three factors does the resistance of a length of wire depend on?
2) Describe the structure of a typical metal.
3) Define amorphous and give an example of an amorphous material.
4) What is plastic deformation.
5) State Hooke's law.

Good luck!

[rrfc]

(Original post by FreddieKeen)
I'm pretty good at G491 and I will try to help any queries anyone may have (it is good for everyone if you post queries).

There hasn't been a lot of discussion here yet so here are some questions for you to get thinking about:

1) What three factors does the resistance of a length of wire depend on?
2) Describe the structure of a typical metal.
3) Define amorphous and give an example of an amorphous material.
4) What is plastic deformation.
5) State Hooke's law.

Good luck!

1- type,size, length
2-
3- never done this in unit 1 ?
4- Non reversible changes in shape
5- E= stress/strain

[FreddieKeen]

(Original post by rrfc)
1- type,size, length
2-
3- never done this in unit 1 ?
4- Non reversible changes in shape
5- E= stress/strain

You are close with your answer to number 1, your vocab is not quite correct though.

Number 3 is in unit 1 and could come up in a paper.

You have got number 4 correct.

"Plastic deformation when a material is permanently stretched; the material will not return to its original shape once the forces are removed"

You have stated the formula for Young's Modulus for number 5, not Hooke's Law.

- - - - - - - - - -

1) What three factors does the resistance of a length of wire depend on?
2) Describe the structure of a typical metal.
3) Define amorphous and give an example of an amorphous material.
5) State Hooke's law.

[hihihihihi]

1) What three factors does the resistance of a length of wire depend on?
R=pL/A so resistivity, length and cross sectional area.
2) Describe the structure of a typical metal.
Positive ions in a crystalline lattice with a sea of delocalised electrons.
3) Define amorphous and give an example of an amorphous material.
A material with no overall pattern in structure and the atoms are arranged in random, glass is an amorphous material.
4) What is plastic deformation.
When permanent deformation of a material occurs.
5) State Hooke's law.
F=ke, where F is the force, k is stiffness constant and e is the extension


Hey do you have the Jan 2012 paper?

[FreddieKeen]

@hihihihihi: All of your answers are correct, I shall write up some more questions later.

I only have the Section A part of the January 2012 paper... Sorry!

Here you go:

[hihihihihi]

(Original post by FreddieKeen)
@hihihihihi: All of your answers are correct, I shall write up some more questions later.

I only have the Section A part of the January 2012 paper... Sorry!

Here you go:

Thanks for the post do you have the mark scheme? also is there anyway you can get section B? I would be really greatful.

[FreddieKeen]

(Original post by hihihihihi)
Thanks for the post do you have the mark scheme? also is there anyway you can get section B? I would be really greatful.

No sorry, don't have a mark scheme. My teacher only emailed our class the Section A questions...

Some more questions:

1) Diffraction and interference are two wave properties. Write down two more.
2) Give one example of a transverse wave.
3) What's the difference between a bit and a byte?
4) Define potential difference.
5) What causes internal resistance?

[hihihihihi]

1) Diffraction and interference are two wave properties. Write down two more.
Refraction and reflection?
2) Give one example of a transverse wave.
electromagnetic wave
3) What's the difference between a bit and a byte?
A bit is a single binary digit and a byte is a group of 8 binary digits ( I had to look this up on revision guide =/)
4) Define potential difference.
v=E/Q so the energy per unit charge.
5) What causes internal resistance?
Electrons in the battery collide with other atoms which makes them lose energy. Thats why a battery usally heats up from this lost energy.
Btw I found a examiners report for jan 2012 exam so tell me if you need it.

[When you see it...]

AT LAST I HAVE FOUND OTHER PEOPLE ON TSR DOING THIS PAPER!
Has anyone got the past paper/mark scheme for G491 and G492? Jan 2012 I mean.

[When you see it...]

Anyone else hate the materials section/questions with a passion?
I'm alright with sensing/electricity though.

[hihihihihi]

Yeah there too many properties to know about.

[FreddieKeen]

Here is a mark scheme I have just made for Physics In Action Section A Jan 2012. (please correct me on anything if wrong)...

[FreddieKeen]

(Original post by hihihihihi)
1) Diffraction and interference are two wave properties. Write down two more.
Refraction and reflection?
2) Give one example of a transverse wave.
electromagnetic wave
3) What's the difference between a bit and a byte?
A bit is a single binary digit and a byte is a group of 8 binary digits ( I had to look this up on revision guide =/)
4) Define potential difference.
v=E/Q so the energy per unit charge.
5) What causes internal resistance?
Electrons in the battery collide with other atoms which makes them lose energy. Thats why a battery usally heats up from this lost energy.
Btw I found a examiners report for jan 2012 exam so tell me if you need it.

Once again, all correct... Well Done

[hihihihihi]

I found the compelete mark scheme for the jan 2012 exam but no questions =/

[When you see it...]

(Original post by FreddieKeen)
1) Diffraction and interference are two wave properties. Write down two more.

Bit vague. Sounds like its from an actual past paper lol. How about:
Wavelength;
Period.
Are they not 'properties' of waves? They ae peoperties of individual waves, but do they qualify as properties of waves in general?

(Original post by FreddieKeen)
2) Give one example of a transverse wave.

Light.

(Original post by FreddieKeen)
3) What's the difference between a bit and a byte?

A bit is a single alternative ("a 0 or 1" it would say on the markscheme) whereas a Byte is 8 alternatives - 8 bits.

(Original post by FreddieKeen)
4) Define potential difference.

The difference in energy per unit charge between two places. Measured in Joules per Coulomb, shortened to Volts.

(Original post by FreddieKeen)
5) What causes internal resistance?

The atoms/particles/ions in each cell colliding with the electrons/positrons/whatever, causing them to dissipate energy, acting as an 'internal' resistance within each cell.

[hihihihihi]

Originally Posted by FreddieKeen

2) Give one example of a transverse wave.

Light.

I think you have to be more specific , so a electromagentic wave

Originally Posted by FreddieKeen

3) What's the difference between a bit and a byte?

A bit is a single alternative ("a 0 or 1" it would say on the markscheme) whereas a Byte is 8 alternatives - 8 bits.

8 bits is 2^8 so 256 alternatives