According to Brynjolfsson and McAfee (2014), if the first machine age helped unlock the forces of energy trapped in chemical bonds to reshape the physical world, the real promise of the second machine age is to help unleash the power of .

human ingenuity

Explanation:

The book: 'The Second Machine Age: Work, Progress, and Prosperity in a Time of Brilliant Technologies' was written in 2014 by Erik Brynjolfsson and Andrew McAfee. This book picks up from their previous book: 'Race Against the Machine'. In this book, they posited that the Second Machine Age involves the use of automation in doing most cognitive tasks which has made humans and software-driven machines substitutes, rather than complements. They contrasted this coming age with what was called the "First Machine Age", or Industrial Revolution , which produced machines for labour.

c. because step up transformer steps up the input voltage i.e increases the input voltage  

the number of turns are greater on the secondary side of step up transformer  

transformer does not handle dc current