Question

The length of two metallic rods at temperatures `theta` are `L_(A)` and `L_(B)` and their linear coefficient of expansion are `alpha_(A)` and `alpha_(B)` respectively. If the difference in their lengths is to remian constant at any temperature then
A. `L_(A)//L_(B)=alpha_(A)//alpha_(B)`
B. `L_(A)//L_(B)=alpha_(B)//alpha_(A)`
C. `alpha_(A)=alpha_(B)`
D. `alpha_(A)alpha_(B)=1`

Answer 1

Correct Answer - B
Change in `L_(A)`=change in `L_(B)`
i.e. `DeltaL_(A)=DeltaL_(B)`
`rArr alpha_(A) DeltaTL_(A)=alpha_(B)DeltaTL_(B)`
or `alpha_(A) L_(A)=alpha_(B) L_(B)`