basic techna

Discussion in 'General Electronics Chat' started by chyadesh, Apr 24, 2009.

  1. chyadesh

    Thread Starter Member

    Apr 10, 2009
    Q) why we don't use 'dc' supply in our house...but only 'ac'?
    not only in our house but for many other purposes.

    Q) Is there advantage in using 'ac' rather than 'dc'...or due to less power loss in transmission make 'ac' more advantageous?

    Q Is there any difference between EMF and voltage?

    Q.. What is the meaning of the words 'Straight polarity'
    'reverse polarity'?
  2. Audioguru

    New Member

    Dec 20, 2007
    AC is used in electricity transmission lines and in the home so that transformers can be used to reduce the voltage. Transformers do not work with DC.
  3. mik3

    Senior Member

    Feb 4, 2008
    They use AC because it is stepped up/down easily with transformers. To make the same voltage conversions at the same power levels with DC you need very expensive electronics.

    Actually, EMF has the same physical meaning as voltage. The term EMF is used more when referring to sources of voltage and the term voltage is used more when referring to voltage drops across components.

    The last question floats. :p
  4. oz7acs

    New Member

    Jul 21, 2007
    the concept of 'reverse polarity' does not make any sense in case of AC-circuits or AC-voltage, but for DC-circuits, it could for example be an electrolytic capacitor, which was turned upside down - that is with its plus pole to ground and the minus pole to a positive voltage. (In case of a high enough voltage the electrolytic capacitor will be destroyed after a while)...