( ( Voltage ( is ( ( the energy ) ( per ( electric charge ) ) ) ) ) ( , ( it ( ( is ( measured ( in ( volts ( per coulomb ) ) ) ) ) . ) ) ) )
(ROOT (S (S (NP (NNP Voltage)) (VP (VBZ is) (NP (NP (DT the) (NN energy)) (PP (IN per) (NP (JJ electric) (NN charge)))))) (, ,) (NP (PRP it)) (VP (VBZ is) (VP (VBN measured) (PP (IN in) (NP (NP (NNS volts)) (PP (IN per) (NP (NN coulomb))))))) (. .)))
Voltage is the energy per electric charge, it is measured in volts per coulomb.
(ROOT (S (NP (NNP Voltage)) (VP (VP (VBZ is) (RB not) (NP (NP (DT the) (JJ same)) (PP (IN as) (NP (NN energy))))) (, ,) (CC but) (VP (VBZ means) (NP (NP (DT the) (NN energy)) (PP (IN per) (NP (NN unit) (NN charge)))))) (. .)))