The pitch of a screw gauge is `1mm` and there are 100 divisions on the cirucular scale While measuring the diameter of a wire the linear scale reads `1mm` and `47th` division on the circular scale coincides with the reference line The length of the wire is `5.6cm` Find the curved surface area (in `cm^(2)`) of the wire in approprinta number of significant (use `pi = 22//7`) .

Answer

`2.6 cm^(2)`

Explanation

Least count `= (1 mm)/(100) = 0.01 m`
Diameter `D = 1mm +(47)(0.01)mm=1.47 mm = 0.147 cm`
Curved surface area `= 2 pi l = pi Dl`
`= (3.14)(0.147)(5.6)=2.6 cm^(2)`