1. So far, we have thought about systems where the number of
particles (N) and the total system energy (E) were fixed. This would
be a reasonably good description of e.g. a closed container of Ar that
is thermally insulated from the environment. Now consider a closed
container of Ar with thin (but impermeable), thermally conducting
walls in a water bath with fixed temperature.
What are the “fixed” properties of the system now?
(A) N,V and E, but not T
(B) N, V and T, but not E
(C) T and V, but not N and E
(D) E and V, but not N and T

2. So far, we have thought about systems where the number of
particles (N) and the total system energy (E) were fixed. This would
be a reasonably good description of e.g. a closed container of Ar that
is thermally insulated from the environment. Now consider a closed
container of Ar with thin (but impermeable), thermally conducting
walls in a water bath with fixed temperature.
What are the “fixed” properties of the system now?
(A) N,V and E, but not T Wrong, T is fixed by the water bath
(B) N, V and T, but not E Correct. E can fluctuate thermally
(C) T and V, but not N and E Wrong, N is conserved the walls are impermeable
(D) E and V, but not N and T Wrong, both N and T are fixed