The influence of nucleus ground state deviation from closed shell or subshell on structure and strength of multipole resonences (MR) was revealed for a light nuclei (A<45). Cross-sections of (e,e') reactions on these nuclei were calculated for all 1hw MR in the region of momentum transfer from photopoint up to 2 Fm^-1 . The contributions of orbital and spin intreanucleus currents into transverse form factors were separated.

The behavior of transverse multipole resonances (MR) in nuclear electroexcitation cross section is a function of momentum q transferred to nucleus and is determined by the interplay of orbital and spin components of nucleon current. The relative contribution of spin current component grows with momentum transfer and with multipolarity of MR. The analysis of electric multipole isovector EJ 1hw (j=l+1/2) --> (j'=l'+1/2) transitions with D j=Dl=1 has shown that contributions of orbital and spin currents into EJ transverse form factors have different signs from q=Eexc up to q=0.5 - 0.7 Fm-1 , where their interference results in a minimum of EJ squared form factor. At the same q the longitudinal CJ form factors for these transitions are close to their maxima. The similarity in the structure of dipole resonances in backward and forward scattering disappears with increasing q : the contribution of above mentioned transitions into transverse form factors vanishes, spin flip transitions begin to dominate in E1 resonances. The contrast in EJ and CJ behaviors for these transitions could be used for identification of wave function configuration. . For light nuclei 12C and 16 O effect of destructive interplay of the currents components was observed at MAMI-A when C1 and E1 form factors of dipole resonances were analyzed.

The wave functions of excited 1hw states were calculated in the particle-core coupling (PCC) version of shell model. In PCC approach wave functions of excited nuclear states are expanded to a set of low-lying states of (A-1) nuclei coupled with a nucleon in a free orbit. All states of (A-1) nuclei which have non vanishing coefficients of fractional parentage to ground state of A nucleus are taken into account. Without violating the Pauli principle, PCC basis can be extended to include the configurations coupled to low-lying collective excitations of the target nuclei.

The results of PCC on energy dependence of E1 strengths at small momentum transfer for all these nuclei are close to photonuclear cross section data.

The results of the particle-core version of shell model were compared with experimental data for E1,M2 and MJmax resonances. The calculated M2 resonances distributions in 28Si and 32S are close to experimental ones and show the role of hole fragmentation among the residual nuclei states in the intermediate structure of multipole strength

The comparison of experimental data on distribution of M4 and M6 strength in 1p- and 1d-2s-shell nuclei with results of calculations based on PCC version of shell model shows a good agreement. The deviation of ground states of nuclei from closed shell or sub-shell is the main origin of observed fragmentation of multipole strength at large momentum transfer.