2007-03-07 23:01:25 · 7 answers · asked by Anonymous in Science & Mathematics ➔ Engineering
In earlier days DC power was used as at that time the power generation was DC. In Kolkata, India DC power is still used at some places.
The speed control in DC motor is much better than AC. The Railways still use DC motor in their engine. The Tramways also used DC for the same reason. Though in recent years VVVF drives are being used as it gives better speed control in AC motor.
Low DC power is used in electronic circuits.
High Voltage DC transmission at 400kV has some inherent advantages over AC and is used in transmission line worldwide.
2007-03-07 23:40:00 · answer #1 · answered by Bishu 3 · 0⤊ 0⤋
Most electronics works on DC and has to be converted from AC either in a power brick or inside. Only a few electronic things like light dimmers work on AC. AC is great for power distribution, lighting, heating and electric motors, but no good for electronics.
2007-03-07 23:26:01 · answer #2 · answered by Anonymous · 0⤊ 0⤋
If everything ran on AC, devices would be gigantic, because you would have transformers everywhere you need different voltage levels intead of a current or voltage divider made of two resistors. Plus batteries don't have the ability to produce AC, and the gain there is obvious. Nobody wants to have to plug their cell phone in to use it.
2007-03-08 05:09:06 · answer #3 · answered by joshnya68 4 · 0⤊ 0⤋
its so coz in labs the small amount of current given out by dc is enough for practical purposes
2007-03-07 23:21:10 · answer #4 · answered by Anonymous · 0⤊ 1⤋
dc current is a direct current it is used for temporary purpose and emergency purpose
2007-03-08 02:04:22 · answer #5 · answered by Anonymous · 0⤊ 0⤋
Mostly because it's what batteries produce.
2007-03-07 23:07:37 · answer #6 · answered by Ian I 4 · 0⤊ 1⤋
i fully agree with the answer given by bishu. his/her answer is more scientific.
2007-03-09 04:41:15 · answer #7 · answered by nightingale 6 · 0⤊ 0⤋