A Rook without any support loses against the Queen _ceteris paribus_. If it stays under the protection of its King it is at last driven off by _Zugzwang_. The following instance will illustrate sufficiently:
If Black to move, the Rook must move away from the King and soon gets lost by White Checking and attacking Rook simultaneously, thus
1 ... R-QR7;
2 Q-Kt5ch.
K-R8;
3 Q-R6ch. The Rook can never go to KR7 on account of the Checkmate by Queen on first row.
3 ... K-Kt8;
4 Q-Kt7ch.
K-R7;
5 Q-R7ch.
K-Kt8;
6 Q-Kt1ch. or 6 Q-Kt8ch.;
Checks and wins the Rook.