power factor across inductive load

Discussion in 'General Electronics Chat' started by mistercode, Oct 2, 2013.

  1. mistercode

    Thread Starter New Member

    May 30, 2013
    A 120 V, 60-Hz source is connected across an inductive load of 100 + j700 0hms.
    a. what is the power factor of the load ?
    b. What size capacitor must be connected across the load (in parallel) to improve the power factor to 0.95,

    I need help in reviewing how to do a problem like this. What I have so far is that I converted the inductive load to polar form:

    707.11ohms<81.87 degrees (the < symbol stands for the polar angle symbol).

    Then should I convert this into a reactance XL to find the impedance then current?

    A full solution with some explanation would help me get on the right track to the rest of my homework.
  2. WBahn


    Mar 31, 2012
    A) This should be in the Homework Help forum.

    B) "A full solution" would be a bit more than helping you get on the right track. We don't work your homework for you.

    C) You need to show YOUR efforts to work YOUR homework. We will then guide you to move further down the path to a solution that YOU work out.

    You've taken some steps toward showing your work. So let's start from there.

    You have a load that is (100+j700)Ω and you have put that in polar form and found it to be 707Ω<81.7°.

    Consider the following:

    Q1) What is the relationship between power factor and the impedance angle of the load?

    Q2) What does the impedance angle of the load need to be in order to have a pf of 95%?

    Q3) What is the relationship between the power factor, the load reactance and the load resistance?

    Q4) What does the load reactance need to be in order to have a pf of 95%?