When the temperature of copper coin is raised by `80^(@)C` its diameter increases by `0.2%`

Options

A. percentage rise in the area of face is 0.4%
B. percentage rise in the thickness is 0.4%
C. percentage rise in the volume is 0.6%
D. coefficient of linear expansion of copper is `0.25xx10^(-4)//.^(@)C`

Explanation

`(triangleA)/(A)xx100=2((trianglel)/(A))xx100`
`implies%" increase in Area"=2xx0.2xx0.4`
`(triangleV)/(V)xx100=3xx0.2=0.6%`
Since `trianglel=lalphatriangleT`
`(trianglel)/(l)xx100=alphatriangleTxx100=0.2`
`impliesalpha=0.25xx10^(-4)//.^(@)C`