Picks active particle with no current (7)
I believe the answer is:
plectra
'picks' is the definition.
('plectrum' can be a synonym of 'pick')
'active particle with no current' is the wordplay.
'active' indicates an anagram (the letters are active/moving).
'with no' is a deletion indicator.
'current' becomes 'I' (physics symbol).
'particle' with 'i' taken out is 'partcle'.
'partcle' anagrammed gives 'PLECTRA'.
(Other definitions for plectra that I've seen before include "Guitar pickers - carp let (anag)" , "Guitar plucking aids" , "Plucky types" , "Bits of plastic maybe" , "Parts for harpsichord" .)