What is the difference between a mistake and an error in the context of physical measurements?

If potential $V = 100 \pm 0.5\,V$ and current $I = 10 \pm 0.2\,A$ are given,what will be the value of resistance?

If $Q = \frac{X^n}{Y^m}$ and $\Delta X$ is the absolute error in the measurement of $X$,and $\Delta Y$ is the absolute error in the measurement of $Y$,then the absolute error $\Delta Q$ in $Q$ is:

If the length of rod $A$ is $3.25 \pm 0.01 \,cm$ and that of rod $B$ is $4.19 \pm 0.01 \,cm$,then the rod $B$ is longer than rod $A$ by:

$A$ physical quantity $P$ is given by $P = \frac{A^3 B^{1/2}}{C^{-4} D^{3/2}}$. The quantity which brings in the maximum percentage error in $P$ is

$A$ capacitor of capacitance $(4.0 \pm 0.2) \mu F$ is charged to a potential of $(10.0 \pm 0.1) V$. The charge on the capacitor is