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Based on the energy method under the solar coronal conditions the MHD stability of neutralized current ropes is considered. It has been sown that the surface screening currents provide the stability of a current rope with respect to kink perturbations. The azimuth magnetic field can significantly exceed the longitudinal one in coronal magnetic flux ropes.

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Alfvan wave penetration with periods exceeding a few tens of minutes generated by convective plasma motions in the lower solar atmosphere is considered. The sharp boundary approximation between the chromosphere and the corona is used. It has been shown that transmission coefficient for Alfven modes does not exceed one percent. Possible mechanisms of wave generation with long periods are discussed.