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Complete the sentence by putting a cross (X) in the box next to your answer - Edexcel - GCSE Physics - Question 3 - 2012 - Paper 1
Question 3
Complete the sentence by putting a cross (X) in the box next to your answer. The output power of a solar panel is the rate of transfer of ☐ A current ☐ B electrons... show full transcript
Worked Solution & Example Answer:Complete the sentence by putting a cross (X) in the box next to your answer - Edexcel - GCSE Physics - Question 3 - 2012 - Paper 1
Step 1
Step 2
Describe the difference between direct current and alternating current.
Answer
Direct current (DC) refers to the flow of electric charge in a constant direction, whereas alternating current (AC) is the flow of electric charge that changes direction periodically. In DC, the voltage remains constant over time, while in AC, the voltage periodically reverses direction.
Step 3
State why a transformer cannot be used to increase this voltage.
Answer
A transformer cannot be used to increase the voltage from the solar panel because it needs to have alternating current (AC) to function. Since the solar panel generates direct current (DC), a transformer would not work.
Step 4
Explain why using solar panels to generate electricity for the National Grid benefits the environment.
Answer
Using solar panels to generate electricity for the National Grid benefits the environment in several ways. Firstly, solar energy is renewable and abundant, reducing the dependency on fossil fuels that produce greenhouse gases and contribute to climate change. Secondly, solar energy generation results in lower air pollution levels, improving public health. Lastly, it supports sustainable energy practices and helps in combating global warming.
Step 5
Calculate the payback time for the solar panels by selling energy to the National Grid.
Answer
To calculate the payback time:
- The homeowner generates 800 kWh annually.
- The payment rate is 40p per kWh. Hence, income per year = 800 kWh * £0.40 = £320.
- The initial cost of the solar panel is £4800.
- Payback time = Initial cost / Annual income = £4800 / £320 = 15 years.
Thus, the payback time for the solar panels is approximately 15 years.