Physics - Practical physics Question with Solution | TestHub

$2\text{f}=10$

$\text{f}=5cm$

$\frac{1}{\text{f}}=\frac{1}{\text{v}}-\frac{1}{\text{u}}$

$\frac{\text{df}}{{\text{f}}^2}=\frac{\text{dv}}{{\text{v}}^2}+\frac{\text{du}}{{\text{u}}^2}$

$\text{df}={\text{f}}^2\left(\frac{\text{dv}}{{\text{v}}^2}+\frac{\text{du}}{{\text{u}}^2}\right)$

u = 10, v = 10,$\text{du}=\frac{1}{10}$,$\text{dv}=\frac{1}{10}$

(as there are 10 division in 1 cm scale, least count is 0.1 i.e., considered as error)

So$\text{df}=25\left(\frac{1}{10{\left(10\right)}^2}+\frac{1}{10{\left(10\right)}^2}\right)=25\left[\frac{2}{10\times 100}\right]$

df = 0.05 so f =(5.00 ± 0.05) cm.