Figure 5 shows part of a lighting circuit in a house - AQA - GCSE Physics - Question 3 - 2020 - Paper 1
Question 3
Figure 5 shows part of a lighting circuit in a house.
Figure 5
What is the frequency of the ac mains electricity supply in the UK?
Tick (✓) one box.
20 Hz
50 Hz
6... show full transcript
Worked Solution & Example Answer:Figure 5 shows part of a lighting circuit in a house - AQA - GCSE Physics - Question 3 - 2020 - Paper 1
Step 1
What is the frequency of the ac mains electricity supply in the UK?
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Answer
The frequency of the ac mains electricity supply in the UK is 50 Hz.
Step 2
Which diagram shows an alternating potential difference?
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Answer
The second diagram shows an alternating potential difference, as it displays a sine wave pattern oscillating above and below the zero voltage line.
Step 3
Calculate the power output of the lamp.
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Answer
To calculate the power output of the lamp, we use the formula:
extpower=extpotentialdifferenceimesextcurrent
Substituting the known values:
extpower=230extVimes0.020extA=4.6extW
Therefore, the power output of the lamp is 4.6 W.
Step 4
Calculate the energy transferred by the lamp when 180 C of charge flows through the lamp.
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Answer
To calculate the energy transferred, we use the equation:
Thus, the energy transferred by the lamp is 41,400 J.
Step 5
Describe the possible hazard and the risk to the electrician of changing the light switch.
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Answer
Hazard: The hazard includes the presence of a live wire or high potential difference.
Risk: The risks associated with changing the light switch are electric shock, which could lead to serious injury or electrical burns, and in severe cases, it could result in death due to electrocution.
