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Two students, P and Q, investigate how the resistance of wire varies with its length - OCR Gateway - GCSE Physics - Question 18 - 2022 - Paper 1
Question 18
Two students, P and Q, investigate how the resistance of wire varies with its length. Each student uses different lengths of the same wire and the same equipment for... show full transcript
Worked Solution & Example Answer:Two students, P and Q, investigate how the resistance of wire varies with its length - OCR Gateway - GCSE Physics - Question 18 - 2022 - Paper 1
Step 1
Compare the resistance per unit length values
Answer
Looking at the resistance per unit length values from both students:
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Student P:
- For 10 cm: 1.6 Ω/cm
- For 20 cm: 1.32 Ω/cm
- For 30 cm: 1.32 Ω/cm
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Student Q:
- For 10 cm: 1.10 Ω/cm
- For 20 cm: 1.00 Ω/cm
- For 30 cm: 1.10 Ω/cm
- For 40 cm: 1.20 Ω/cm
- For 50 cm: 1.10 Ω/cm
The values from Student P vary more widely than those from Student Q. Student Q's measurements fluctuate but are generally closer to the manufacturer's stated value (1.2 Ω/cm).
Step 2
Evaluate the accuracy of each student's data
Answer
In terms of accuracy:
- Student P's data generally shows higher resistance values which might indicate deviations due to experimental error. This suggests that it is less accurate.
- Student Q's data, particularly for the 40 cm measurement which is closest to the manufacturer's value, indicates that Student Q has recorded measurements that are consistently within a more acceptable range relative to the manufacturer's stated resistance.
Step 3
Evaluate the precision of each student's data
Answer
Regarding precision:
- Student P shows varying results, particularly an inconsistent mean resistance.
- Student Q has consistent measurements across trials, especially in its mean resistance values which tend to be consistent across repeated trials for each length, indicating a higher precision.
Step 4