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Making measurements and analysing data

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Question 16

A student determines the resistivity ρ \rho\,ρ of a uniform metal wire using the equation:

ρ=πRd24L \rho = \frac{\pi R d^2}{4 L} ρ=4LπRd2​

where R R\,R is the electrical resistance of the wire, d d\,d is its diameter, and L L\,L is its length.

The student measures these quantities with the following percentage uncertainties:

  • Percentage uncertainty in R=1.5%R = 1.5\%R=1.5%
  • Percentage uncertainty in d=2.2%d = 2.2\%d=2.2%
  • Percentage uncertainty in L=0.8%L = 0.8\%L=0.8%

What is the percentage uncertainty in the calculated value of ρ\rhoρ?

2.9%2.9\%2.9%

4.5%4.5\%4.5%

5.1%5.1\%5.1%

6.7%6.7\%6.7%

Making measurements and analysing data Questions

  1. A Level
  2. /Physics
  3. /Making measurements and analysing data