strenuous vs voltaic

strenuous

adj
  • Having great vigour or energy; forceful. 

  • Requiring great exertion; very laborious 

voltaic

adj
  • reminiscent of the action of electricity: thrilling, shocking, dramatic. 

  • producing electricity by chemical action. 

  • of or relating to electricity. 

How often have the words strenuous and voltaic occurred in a corpus of books? (source: Google Ngram Viewer )