The internal and external diameters of hollow cylinder measured with vernier callipers are $(5.73 \pm 0.01) \mathrm{cm}$ and $(6.01 \pm 0.01) \mathrm{cm}$ respectively. Then, the thickness of the cylinder wall is

The error in the measurement of resistance, when $(10 \pm 05)$ A current passing through it produces a potential difference of $(100 \pm 6) \mathrm{V}$ across it is

The equation of motion of a damped oscillator is given by $m \frac{d^2 x}{d t^2}+b \frac{d x}{d t}+k x=0$. The dimensional formula of $\frac{b}{\sqrt{k m}}$ is