Question

A thin brass sheet at `20^(@)C` and a thin steel sheet at `30^(@)C` have the same surface area. The common tempreture at which both would have the same area is (Coefficient of linear expansion for brass and steel are respectively, `19xx10^(-6)//^(@)C` are `11xx10^(-6)//^(@)C`)
A. `-6.25^(0)C`
B. `+6.25^(0)C`
C. `-3.25^(0)C`
D. `+3.25^(0)C`

Answer 1

Correct Answer - B
`(A_(2))_(brass)=(A_(2))_(steel)`
`(A_(1))_(br)[1+beta_(Br)(t-20)]=(A_(1))_(st)[1+beta_(st)(t-30)]` Given `(A_(1))_(br)=(A_(1))_(st)`