The pitch of a screw gauge is a mm and there are 100 division on the circular scale. While measuring the diameter of a wire, the linear scale reads 1mm and 47th division on circular scale coincides with the reference line. The length of the wire is 5.6 cm. Find the curved surface area `(in cm^2)` of the wire in proper significant figures.

Answer

`2.6cm^2`

Explanation

Value of 1 MSD =1mm = 0.1 cm.
Value of `1 CSD = (1)/(100)mm = 0.001cm.`
Here, diameter, d =1.47mm = 0.147cm.
I 5.6cm
Curved surface area of wire
A =`2pi rxxi = pixx dxxI`
`=(22)/(7)xx(0.147)(5.6)cm^2 =2.5872cm^2`
Rounding off to two significant figures,
`A =2.6 cm^2`