( ( Just ( as ( ( ( moving ( a magnet ) ) ( past ( a coil ) ) ) ( will ( generate ( a current ) ) ) ) ) ) ( , ( ( ( a ( collapsing ( magnetic field ) ) ) ( around ( a coil ) ) ) ( ( ( creates ( a current ) ) too ) . ) ) ) )
(ROOT (S (SBAR (RB Just) (IN as) (S (S (VP (VBG moving) (NP (DT a) (NN magnet)) (PP (IN past) (NP (DT a) (NN coil))))) (VP (MD will) (VP (VB generate) (NP (DT a) (JJ current)))))) (, ,) (NP (NP (DT a) (VBG collapsing) (JJ magnetic) (NN field)) (PP (IN around) (NP (DT a) (NN coil)))) (VP (VBZ creates) (NP (DT a) (JJ current)) (ADVP (RB too))) (. .)))
Just as moving a magnet past a coil will generate a current, a collapsing magnetic field around a coil creates a current too.
(ROOT (S (NP (NNP Alternative) (JJ current)) (VP (VBZ is) (VP (VBN produced) (SBAR (WHADVP (WRB when)) (S (NP (DT a) (NN magnet) (CC or) (NN coil)) (VP (VBZ moves) (ADVP (RB back) (CC and) (RB forth)) (ADVP (RB repeatedly))))))) (. .)))