AQA GCSE Physics Unit 1 - 20th June 2012 - MY UNOFFICIAL MARK SHEME

Updated Unofficial mark scheme: (Not in order - I am missing some questions but the total amount of questions listed below is worth around 55 marks). If there are any corrections, please say so and we'll discuss them.

1)
a) The stove emits radiation very well as it is a dark matt surface. This emmission can only happen if the surface absorbs hence, black matt is also a good absorber. 2 marks
b) Efficiency = 90% or equivilent. 2 marks
c) Wasted energy could be chemical,light,sound or heat(to stove). 1 mark
d) environmental advantages of stove:less fossil fuels burnt,less C02,global warming and less S02,acid rain and the C02 is used up,by the wood when it grew to compensate for the C02 produced when burnt. 2 marks

2)
a) Graph interpretation: As the load in newtons increases, the amount of input energy also increases. The energy input increases constantly. 2 marks
b) Energy transfer was 2 550 000J. 3 marks
c) The motor uses gravitational potential energy or kinetic. 1 mark
d) Wasted energy is dissipated into the surroundings and heats the surroundings. 2 marks

3)
a) Pumping cold water beneath the Earth's atmosphere where there are hot rocks. These hot rocks are used to heat up the water, turn it into steam and used to turn a turbine to generate electricity. 1 mark
b) Energy is saved when the water is pumped and stored in dams so that energy can be used for future demands. Storage also allows fast production of energy when there is an unexpected surge. 2 marks
c) - 6 MARK QUESTION

Offshore wind turbines
Advantages: Less pollutant gases and therefore makes Britain enviormentally friendly. It is also a renewable energy resource.
Disadvantages: Could effect many habitats such as animals (Birds). The reliabilty of the wind turbines for producing electricity is not very high.

Undersea National grid
Advantages: Not effected badly in bad weather. The electricity gained could be used to reduce fossil fuels,C02,Global warming,S02,acid rain etc.More Hydroelectric electricity will allow more pump storage systems,allowing the national grid to be able to compensate for variations in demand of electricuty better.
Disadvantages: Expensive as waterproof casing will be needed. It could also effect many sea creatures such as fish and other.

4)
a) Metals have free delocalised electrons which can help transfer energy through out the metal when they gain energy from the heat source. Particles also vibrate which increases the spread of energy throughout the metal. 4 marks
b) (Not sure where this question goes so I just slipped it in here!) Gas particles have high amounts of kinetic energy. When they come in contact with a cold surface or an obstacle, the gas loses energy and the particles contract which means they become more closer together. This means the particles have less energy and the gas eventually turns into a liquid. 2 marks

5)
a) Double glazing has a lower U-Value meaning that less energy is transferred to the outside of the window and thus less condensation occurs because condensation is accelerated,with a higher surface temperature. 2 marks
b) The U-Values for the double glazed windows was much more higher which makes them more effective at reducing heat transfer and acting as an insulator rather than the single glazed window. The double glazed companies are more expensive than the single glazed but they are still more effective. 3 marks

6)
a) Light rays drawn and reflected from bulb onto mirror,at two points,angle i=angle r and the 4 lines extend into the mirror until two of the lines cross,in the eyes perspective range, and then the virtual light bulb must then be same distance in front as behind the mirror. 4 marks
b) It is a virtual image because it isn't generated by real light rays. 1 mark

7) a)Microwaves and radiowaves have similar properties (Large wavelength, smaller frequency) and travel through a vaccum. 2 marks
b) The signal from the radiowaves will be better than terrestrial waves because radiowaves can diffract more and therefore, spread more so that the signal can be picked up. Terrestrial waves on the other hand diffract but not enough for the signal will to be picked up. 3 marks
c) Microwaves can pass through the Earth's atmosphere and to the sattelites in space. 2 marks
d) Frequency = 1,200,000 Hz. 2 marks

8) a) 2880p - Escalator one. 3 marks

9)a)Red shift is the increase in wavelength due to galaxy's moving further away from Earth. The big bang theory claims that the universe started with an explosion which caused expansion. Therefore, the planets are moving away from us. 3 marks
b) After the big bang, high levels of CMBR were found in space which can be used as evidence to help prove the big bang theory. 1 mark
c)The origin was the small initial point of matter. 1 mark
d)lLarger wavelengths as the universe was exanding and therefore, more radiation would spread out. 2 marks

These are what I think the marks were for each of these questions,most of these I'm certain of,including ray diagram was definitely 4 and the pump storage system was only 2.

Thanks to someone, I realised there was an independent scientist question. The answer was that so there is no bias from the company itself. Independent scientists would favour neither side. Can you please update the mark scheme so I can put it up on the first page! Thanks!

Thanks to someone, I realised there was an independent scientist question. The answer was that so there is no bias from the company itself. Independent scientists would favour neither side. Can you please update the mark scheme so I can put it up on the first page! Thanks!

Thanks to me

What question?-I can't remember it

Why are independent scientists used rather than people in the company itself?

I still can't remember it-what questions was it near to?and what di you write?

The answer was to avoid bias. Independent scientists will favour neither side. The question was next to the questions about satellites and microwaves. It was a question on the top right of a page.

Well I can't edit the mark scheme for you because I can't even remember such a question.

I think I got most of these right, at least an A I think.


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Well I can't edit the mark scheme for you because I can't even remember such a question.

There wasn't 9 questions it was 8 question altogether.

My pleasure. Any Science exam requests, please assure me.

What was the answer to the condensation question ???

Can you please make a unofficial mark scheme for chemistry 1 new spec 15th june.