A blacksmith heated a metal whose cubic expansivity is 6.3 x 10\(^{-6}\)K\(^{-1}\). The area expansivity is
- 2.0 x 10-6K-1
- 2.1 x 10-6K-1
-
4.2 x 10-6K-1
- 6.3 x 10-6K-1
The correct answer is: C
Explanation
If the lineal expansivity = ∝
=> area expansivity β= 2∝.
And cubic expansivity δ = 3∝.
=> 6.3 x 10\(^{-6}\) = 3∝
∴ ∝ =
| ∴ ∝ = | 6.3 x 10-6 | = 2.1x 10-6 |
| __3 |
∴ Area = 2∝ = 2 x 2.1x10\(^{-6}\)
= 4.2 x 10\(^{-6}\)K\(^{-1}\)