The invention uses one inductor, which is formed of one, two or a few twisted or parallel conductors, and exposes a sample object in a pulsed and damped alternating magnetic field (B) without necessarily the employment of a second, constant intensity, magnetic field. In this way, the nuclei and/or the electrons of the sample object are activated, in the presence of a non-constant magnetic field (B), that gets infinite negative and positive values between successive damped positive and negative values, crossing through the zero value during a magnetic pulse. Thus, a wide nuclear NMR and electronic EPR multiple--resonance of the sample object is achieved.