UnScramble this Word: n f f s e l s i?

Questions

Instrument that records, on paper or film, wave patterns that are equivalent to the oscillations of an electric voltage, or that converts mechanical oscillations into an equivalent electric current before recording them on paper or film in the form of wave patterns?

Instrument that utilizes the phenomenon of interference of light waves for the ultraprecise measurement of wavelengths of light itself, of small distances, & of certain optical phenomena?

Instrument used to measure electric current?

Intelligent people have more _____ & copper in their hair.?

International geophysical program, initiated in 1984, for surveying the deep ocean floor & its resources?