The natural length of a metallic root at `0^(@)C` is `l_(1)` at `theta^(@)C` is `l_(2)`. The given lengths of the rod at `theta^(@)` is `l_(3)`, then:

Options

A. The thermal stress in the rod is non zero if `l_(3)gtl_(2)`
B. The strain in the rod is zero if `l_(2)!=l_(3)`
C. The thermal stress in the rod is non-zero if `l_(3)ltl_(2)`
D. The thermal stress and strain will be zero if `l_(2)=l_(3)`

Explanation

A, C, D