Why often we use a small value of dc voltage as compared to ac voltage.?

Question

Why often we use a small value of dc voltage as compared to ac voltage.?

Answer 1

We use AC because it is more efficient to send over power lines. DC is the natural output of a battery. The higher voltage levels allow for lower current and smaller wires.

Answer 2

Several reasons:

1. Because DC voltages are used locally, that is, they do not travel long distances to get to you.

2. DC are generated by batteries that operate from chemical reactions that supply 1 to 2 volts.

3. DC voltages are commonly used to operate electronic circuits, most of which operate from low voltages in the 5 to 20 volt range.

4. AC voltages can be easily transformed to different voltage levels with transformers. This makes them useful for delivery over long distances, as they can be transformed t high voltages for low losses.

5. AC voltages used in the home are at a level of 120 or 240 volts, which is a good compromise. Higher increases the risk of shock, lower means the wires have to be too heavy.

6. AC power in the home is used for high power appliances that require thousands of watts, which requires a voltage of hundreds of volts to allow them be powered with reasonable size wire.

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