An iron wire AB has diameter of 0.6 mm and length 3 m at `0^(@)C`. The wire is now stretched between the opposite walls of a brass casing at `0^(@)C`. What is the extra tension that will be set up in the wire when the temperature of the system is raised to `40^(@)C`?
Givne `alpha_("brass")=18xx10^(-6)//K`
`alpha_("iron")=12xx10^(-6)//K`
`Y_("iron")=21xx10^(10)N//m_^(2)`

Options

A. 14.2 N
B. 13.8 N
C. 16.3 N
D. 21.7 N

Answer

A