Mark the correct options :

Options

A. A sustem X is thermal equilibrium with Y but not with Z. System Y and Z may be in thermal equilibrium with each other.
B. A system X is in thermal equilibrium with Y but not with Z. Systems Y and Z are not in thermal equilibrium with each other.
C. A system X is neither in thermal equilibrium with Y nor with Z. The systems Y and Z must be in thermal equilibrium with each other.
D. A system X is neither in thermal equilibrium with Y nor with Z. The systems Y and Z may be in thermal equilibrium with each other.

Answer

B, D

Explanation

According to question, `T_(x)=T_(y)`
x and y are in thermal equilibrium `T_(x)!=T_(z)`
`:.T_(y)!=T_(z)" ":.` Option (B) is correct.
Now `T_(x)!=T_(y)` and `T_(x)!=T_(z)`
`:.` System Y and Z may be in thermal equilibrium and may not be.
`:.` Option (D) correct.