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10 (a) Figure 13 shows wind turbines, used to generate electricity for the National Grid - Edexcel - GCSE Physics - Question 10 - 2021 - Paper 1
Question 10
10 (a) Figure 13 shows wind turbines, used to generate electricity for the National Grid. The wind turns the turbine blades. The wind is a renewable source of energ... show full transcript
Worked Solution & Example Answer:10 (a) Figure 13 shows wind turbines, used to generate electricity for the National Grid - Edexcel - GCSE Physics - Question 10 - 2021 - Paper 1
Step 1
Step 2
2. For one turbine - the energy input per second from the wind is 6.2 kJ - the energy output per second to the National Grid is 2.2 kJ. Calculate the efficiency of this turbine.
Answer
To calculate the efficiency of the turbine, we use the formula:
ext{efficiency} = rac{ ext{Energy Output}}{ ext{Energy Input}} imes 100Substituting the values:
ext{efficiency} = rac{2.2 ext{ kJ}}{6.2 ext{ kJ}} imes 100 = 35.48\\% ext{ (rounded to } 35 ext{%) }Step 3
3. Suggest a reason why it is impossible for the turbine to use all the kinetic energy of the wind.
Answer
It is impossible for the turbine to use all the kinetic energy of the wind because not all of the air hits the blade, and some energy is always transferred to thermal energy due to friction within the turbine.
Step 4
(b) Nuclear fission and nuclear fusion are two non-renewable sources of energy. Compare nuclear fission and nuclear fusion as possible sources for generating electricity using a nuclear reactor.
Answer
Comparison of Nuclear Fission and Fusion
Differences:
- Fission: Fission involves the splitting of a heavy nucleus (like uranium) by a neutron, resulting in two daughter nuclei, more neutrons, and energy release, which can start a chain reaction.
- Fusion: Fusion involves the joining of light nuclei (like hydrogen) at high energy/temperature/pressure, releasing energy (e.g., helium and energy).
Advantages and Disadvantages:
Advantages:
- Fission: Already in use for power generation.
- Fusion: Does not produce harmful waste products.
Disadvantages:
- Fission: Generates radioactive waste that is hard to dispose of and poses a risk of accidents.
- Fusion: Not yet achieved on a practical scale; poses challenges in achieving necessary energy/temperature/pressure conditions.