Questions & answers: 1. Frequency (1)
2. Reflected sound wave = Echoes
3. Spread out, same as (2)
b) vibrations are parallel to the direction of energy transfer (2)
4. Expensive as National Grid is a long distance away from rural areas (1)
4b) ADVANTAGES
constant supply, little variation in output
£30k cheaper than wind turbine
renewable resource
doesn’t produce as much noise as wind
No CO2
DISADVANTAGES
could ruin ecosystem by preventing free movement of fish
May need maintenance unlike wind
Lower power output - 8W compared to 10W
Wind - ADVANTAGES
higher average output
Needs little maintenance
renewable resource
Easily expanded
No CO2
DISADVANTAGES
Eyesore
noise pollution
Wind speeds vary, meaning there could be times of under- or oversupply
Costs 50k, 30k more than HEP (6)
5. inefficient as less or little energy used to heat food as heat is lost as infrared radiation to the surroundings(2)
b) properties of microwaves and infra-red radiation (2): can diffract, can refract, travel same speed in vacuum, both transverse waves, can be reflected
calculation questions, 340 m/s for first one (2) then Specific heat capacity 78 degrees(3) , then 6.4 watts(2) then 0.07 degrees/s (2) efficiency question was 0.48 W (2)
6. Fins increase surface area and black matt are good absorbers of heat (2)
7. Cosmic microwave background radiation (1)
b) provides evidence for the big bang theory (1)
10. They keep costs as low as possible as efficiency does not increase as much but the cost goes up rapidly, (give example and data figures to secure the marks) (2)
11. Why France will still use nuclear power (2) : cost of electricity is cheaper(1) and produces much more electricity(1) , produces no greenhouse gases like co2(1)
12. Disadvantages of nuclear power stations (2): raw materials are non- renewable, high decommissioning costs, produces radioactive waste.
13. Factors that affect rate of energy transfer of mug (2): room temperature, surface area.
b) Particles gain kinetic energy and collide more frequently, passing on their extra kinetic energy to other particles. (2)
c) how is a convection current formed in the mug(4): liquid at the bottom is heated and particles gain kinetic energy and move away from each other, this makes the liquid less dense , causing it to rise and displace the denser colder air at the top , the denser particles then fall and is heated again.
14) Control variable for the investigation measuring rate of evaporation (1): same beaker or same type of beaker, same position in the room. Same thermometer.
Source-
http://gcseanswers.co.uk/physics