- Home
- Standard 11
- Physics
1.Units, Dimensions and Measurement
medium
The relative error in resistivity of a material where
resistance $= 1.05 \pm 0.01\, \Omega$
diameter $= 0.60 \pm 0.01\, mm$
length $= 75.3 \pm 0.1 \,cm$ is
A
$0.04$
B
$0.40$
C
$0.08$
D
$0.01$
Solution
$\mathrm{R}=\frac{\rho \ell}{\mathrm{A}}$
$\rho=\frac{\mathrm{RA}}{\ell}=\frac{\mathrm{R} \pi \mathrm{r}^{2}}{\ell}=\frac{\pi \mathrm{d}^{2} \mathrm{R}}{4 \ell}$
$\frac{\Delta \rho}{\rho}=\frac{\Delta \mathrm{R}}{\mathrm{R}}+\frac{\Delta \mathrm{d}}{\mathrm{d}}+\frac{\Delta \ell}{\ell}$
Standard 11
Physics
