Resistors and Ohm's Law Video Lessons

Concept

# Problem: R=ρL/A,  where L is the length and A is the cross-sectional area of the wire. From the wire in question 4, the length of the wire is 10m, the cross-sectional area of the wire is 3.25 × 10^-3 cm^2. The relative uncertainty of L and A are both 10%. What are the resistivity and its uncertainty of the wire? The value of R is 1.345 ohms. Please write the symbolic equation first, then calculate the relative uncertainty, and finally the absolute uncertainty.ρ = δρ/ρ = δρ = Express ρ in standard form:

###### FREE Expert Solution

In this problem, we are dealing with the propagation of uncertainties.

We'll need the rules of propagation of uncertainties:

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###### Problem Details

R=ρL/A,  where L is the length and A is the cross-sectional area of the wire. From the wire in question 4, the length of the wire is 10m, the cross-sectional area of the wire is 3.25 × 10^-3 cm^2. The relative uncertainty of L and A are both 10%.

What are the resistivity and its uncertainty of the wire? The value of R is 1.345 ohms. Please write the symbolic equation first, then calculate the relative uncertainty, and finally the absolute uncertainty.

ρ =

δρ/ρ =

δρ =

Express ρ in standard form: