A student carries out an experiment to determine the resistivity of a metal wire - AQA - A-Level Physics - Question 8 - 2018 - Paper 1
Question 8
A student carries out an experiment to determine the resistivity of a metal wire. She determines the resistance from measurements of potential difference between the... show full transcript
Worked Solution & Example Answer:A student carries out an experiment to determine the resistivity of a metal wire - AQA - A-Level Physics - Question 8 - 2018 - Paper 1
Step 1
A current
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The uncertainty in the current measurement does not significantly affect resistivity calculations because resistivity depends mainly on resistance, length, and area.
Step 2
B diameter
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The diameter measurement affects the cross-sectional area, which is critical in determining resistivity. Given the formula for resistivity, uncertainty in diameter has a substantial impact.
Step 3
C length
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The length measurement has a lesser impact because although it contributes directly, the influence of area governed by the diameter has greater significance in the overall calculation of resistivity.
Step 4
D potential difference
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Uncertainty in potential difference affects the resistance calculation, but the resistivity formula primarily relies on both length and cross-sectional area.
Step 5
Conclusion
97%
117 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Among these options, the measurement that gives the largest uncertainty in the calculated value of resistivity is therefore B) diameter, as it impacts the area used in the resistivity formula more heavily than the other variables.
