Amperage Question

Discussion in 'General Electronics Chat' started by JBolan, Sep 27, 2009.

  1. JBolan

    Thread Starter New Member

    Sep 27, 2009
    If anyone can help with these questions it will be a great help.

    What is the amperage of a 30 ohm resister with a 6volt power supply?

    A 120 volt amp capacitor with a secondary coil 24 volts. What is the secondary in rush current?
  2. mik3

    Senior Member

    Feb 4, 2008
    Ohm's law is:


    Have a try.
  3. zimbarak

    Active Member

    Feb 8, 2009
    as a reply for your question!

    u can calculate the amperage by using the ohms's law with i=v/r 6/30 it will give u 0.2 a = 200 ma !

    2nd question didnt get u wll ! plz explain more !

  4. kkazem

    Active Member

    Jul 23, 2009
    Hi JBolan,
    For the first question, the previous reply is exactly right. Ohms Law: E/I=R, so in your case, 6V/30 Ohms = 0.2 amps = 200 mA.
    Your second question makes no sense as you wrote: "A 120 volt amp capacitor with a secondary coil 24 volts. What is the secondary in rush current?"

    First, caps are not rated in volt ampere and they don't have coils either, whether secondary or not. Please clarify what you're talking about. Is it a motor start contactor that switches in a large cap for motor starting, then when the motor comes up to speed, it switches the large cap out and switches in a smaller, run cap. I'd need the capacitance and line voltage to compute the inrush current, as well as the motor winding resistance & winding inductance (winding impedance).

    If you reply and clarify that, I'll help you with it.

    Kamran Kazem
  5. KitCarlson


    Sep 27, 2009
    120 volt amp capacitor / 24 volts = 5A

    Read about volt ampere reactance in AC circuits.

    Often known as kvar (kilo-volt ampere reactive) by power people.