Alternating Current has its advantage over Direct Current because?

Mainly,'cause it's so easy to step up or step down

And generator brushes last longer on slip rings.


Haven't really helped with the multiple choice, have we Dale?

Ah yes Rog, of course

Not just a whole lot

https://www.google.com/?gws_rd=ssl#q=advantages+ac+over+dc

I'm not sure there is anything about AC current or voltage that is more easily measured than DC. Neither am I persuated AC is any cheaper to produce (ie. generate froim mechanical energy). (Unloaded DC generators do have their problems though.)


However the lower line losses are certainly a siugnificant advantage to AC and it is far easier to rectify AC signals to produce DC at high powrer levels than it is to procuce AC power from DC, If that is what you mean by greater variety, then I agree.

1. Easier to produce via turbines.
2. Safer, as you won't get 'stuck' to an AC wire when you touch it, but you could on a DC one.

Any rotsating machine csan drive an AC or a DC generator wiih equal ease.Turbo generators producing AC aere indeed ubiquitous, but that is becsuse of Westinghouse's triumph over Edison/GE and the relatively lower line losses associayted with AC,

For new lines, beyond the ‘break-even’ distance, HVDC transmission systems cost less, even with the added expense of terminal stations. An HVDC line has lower power losses than an HVAC of the same capacity in practically all cases, which means more power is reaching its final destination. Also, by converting an ac line to dc, it may be possible to raise the power transfer capability of an existing transmission corridor. HVDC may be the most cost effective solution for long distance bulk power transfer.

http://new.abb.com/systems/hvdc/why-hvdc/economic-and-environmental-advantages

I don't think so. Aren't induction generator aka dynamos the simplest device to produce electricity? And don't they profuce AC?

The safety aspect is also significant. Irrespective of what the grid uses, domestic connections must be in AC for safety reasons.