Question

The external and internal diameters of a hollow cylinder are measured to be $\left(4.23\pm 0.01\right)$ cm and $\left(3.89\pm 0.01\right)$cm. The thickness of the wall of the cylinder is

• A. $\left(0.34\pm 0.02\right)$cm
• B. $\left(0.17\pm 0.02\right)$cm
• C. $\left(0.17\pm 0.01\right)$cm
• D. $\left(0.34\pm 0.01\right)$cm

Answer 1

Answer: (C)

$D=\left(4.23\pm 0.01\right)cm$

$d=\left(3.89\pm 0.01\right)cm$

$\Delta t=\left(D-d\right)/2=\left[\left(4.23\pm 0.01\right)-\left(3.89\pm 0.01\right)\right]/2$

$=\left[\left(4.23-3.89\right)\pm \left(0.01+0.01\right)\right]/2$

$=\left(0.34\pm 0.02\right)/2cm=\left(0.17\pm 0.01\right)cm$