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

Thermal equilibrium means there is no temperature difference between the bodies and there will be no exchange of energy between them.

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 (d) is correct.