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A hybrid car has an electric motor and a petrol engine - AQA - GCSE Physics Combined Science - Question 3 - 2019 - Paper 1
Question 3
A hybrid car has an electric motor and a petrol engine. Petrol is a non-renewable energy resource. What is meant by a non-renewable energy resource? [1 mark] The ... show full transcript
Worked Solution & Example Answer:A hybrid car has an electric motor and a petrol engine - AQA - GCSE Physics Combined Science - Question 3 - 2019 - Paper 1
Step 1
Step 2
Calculate the current used to charge the battery.
Answer
To find the current, we use the formula: where:
- P is the power (in watts),
- V is the voltage (in volts),
- I is the current (in amperes).
Given:
- P = 6.9 kW = 6900 W,
- V = 230 V,
We can rearrange the formula to find I: Substituting the known values:
Step 3
Explain the difference between direct and alternating potential difference.
Answer
Direct potential difference (DC) is a constant voltage that flows in one direction only. In contrast, alternating potential difference (AC) changes direction periodically, which means the voltage can fluctuate in both positive and negative cycles.
Step 4
Explain why it is better to use a cable with a low resistance than to use a cable with a high resistance.
Answer
Using a cable with low resistance is preferable because it allows for lower power loss due to heat dissipation during transmission. This efficiency means that more of the electrical power reaches the device being supplied, and the cable will not overheat, ensuring safety and better performance.