  The previously proposed Heisenberg-type relation $ E_c t_c >> \hbar {\cal C}$
for the energy used by a quantum computer, the total computation time and the
logical ("classical") complexity of the problem is verified for the following
examples of quantum computations: preparation of the input state, two
Hamiltonian versions of the Grover's algorithm, a model of "quantum telephone
directory", a quantum-optical device factorizing numbers and the Shor's
algorithm.
