Consider a hypothetical situation where we are comparing the properties of two crystals made of atom `A` and atom `B`. Potential energy `(U) v//s` interatomic separation (r) graph for atom `A` and atom `B` is shown in figure (i) and (ii) and respectively.

It is seen that the potential energy can reach a maximum value of `U_(T)` at temperature `T= 10K`. if `r_(1)` and `r_(2)` are `0.9999 r_(0) "and" 1.0003 r_(0)` for atoms of crystal `A`, its approximate coefficient of linear expansion can be :-

Options

A. `4xx10^(-5)//K`
B. `1 xx 10^(-5)//K`
C. `2 xx 10^(-5)//K`
D. `3 xx 10^(-5) //K`

Answer

C

Explanation

We have `Deltar_("avg") = ((1.0003-0.9999)/(2)) r_(0)` (from equilibrium position)
`therefore (Deltar)/(r_(0)) = alpha DeltaT implies alpha = 2 xx 10^(-5)//K`