Question

Coefficient of linear expansion of brass and steel rods are `alpha_(1)` and `alpha_(2)`. Length of brass and steel rods are `l_(1)` and `l_(2)` respectively. If `(l_(2) - l_(1))` is maintained same at all temperature, which one of the following relations holds good?
A. `alpha_(1) l_(2) = alpha_(2) l_(1)`
B. `alpha_(1) l_(2)^(2) = alpha_(2) l_(1)^(2)`
C. `alpha_(1)^(2) l_(2) = alpha_(2) l_(1)`
D. `alpha_(1) l_(1) = alpha_(2) l_(2)`

Answer 1

Correct Answer - D
Change in length for both rods should be same
`Delta l_(1) = Delta l_(2)`
`l_(1)alpha_(1)Delta T = l_(2) alpha_(2) Delta T`
`l_(1) alpha_(1) = l_(2) alpha_(2)`.