The length of a rod is 2.5 cm and diameter is 2.5 mm. The volume of the rod with due consideration to significant figures is

Explanation

l=2.5 cm ,
diameter = 2.5 mm = `2.5 xx 10^(-1) cm = 0.25` cm,
Radius r = 0.125 cm
Volume of the rod `= pi r^2 l`
`=3.1428 xx 0.125 xx0.125xx2.5`
Here 2.5 has two significant figures. Round off the remaining numbers to 2+1 = 3 significant figures.
`therfore ` Volume of the rod `= 3.14xx0.125xx0.125xx2.5`
`=0.1226`
This has to be rounded off to two significant figures. The result is 0.12` cm^3`