Question

A system X is neither in thermal equilibrium with Y nor with Z. The systems Y and Z:

• A. Must be in thermal equilibrium
• B. Cannot be in thermal equilibrium
• C. May be in thermal equilibrium
• D. None of these

Answer 1

The correct option is C

May be in thermal equilibrium

Let the temperatures of X, Y and Z be T_x, T_y and T_z, respectively.
Now,
T_x ≠ T_y and T_x ≠ T_z
This does not tell us anything about T_y and T_z, except that they are not equal to T_x.
So, T_y = T_z, and T_y ≠ T_z, both are possibilities!
Hence, option (c) is correct.