When the temperature of a copper coin is raised by `80^@C`, its diameter increases by `0.2%`.

Options

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

Answer

A, C, D

Explanation

`(DeltaA)/(A)xx100=2((Deltal)/(A))xx100`
`%` increase in area`=2xx0.2=0.4`
`(DeltaV)/(V)xx100=3xx0.2=0.6%`
Since `DeltaI=IalphaDeltaT`
`(Deltal)/(l)xx100=alphaDeltaTxx100=0.2`
`alpha=0.25xx(10^-4^@)/(C )`