Homepage - RF Cafe
Webmaster: Kirt Blattenberger | KB3UON | Sitemap | ©1996-2014     Visit RF Cafe on
      Menu below is just a small sample of what is here!          Visit RF Cafe on Facebook Visit RF Cafe on Twitter Visit RF Cafe on LinkedIn
Custom Search
More than 10,000 searchable pages indexed.
•−•  ••−•    −•−•  •−  ••−•  •
RF Cafe Morse Code >Hear It<

Quiz on AC Circuit Theory
December 1970 Popular Electronics

December 1970 Popular Electronics

December 1970 Popular Electronics Cover - RF Cafe  [Table of Contents]People old and young enjoy waxing nostalgic about and learning some of the history of early electronics. Popular Electronics was published from October 1954 through April 1985. All copyrights (if any) are hereby acknowledged.
Here is a fairly simple quiz on AC circuit analysis. If you are not already comfortable with adding series and parallel circuits containing resistors, capacitors, and inductors, you will appreciate the simple formula presented that will keep the sweat level down ;-)  OK, pick up you pencils... now.





See all articles from Popular Electronics.

Quiz on AC Circuit Theory

By Robert P. Balin

Voltage measurements made in a series ac circuit seldom add up as simply as they do in a dc circuit. You may even find the voltage across a coil or capacitor to be greater than the supply voltage! Nevertheless, Ohm's Law and Kirchhoff's Law do apply, and careful measurements will show that the supply voltage and the various voltage drops around a series ac circuit are related in an unusual way: the square of the supply voltage is equal to the square of the difference between the voltage on the coil and the voltage on the capacitor, plus the square of the voltage on the resistor.

This relationship, (VTotal)2 = (VL - VC)2 + (VR)2,can be used to find any unknown voltage if all others are known.

In parallel ac circuits, the currents add up the same way as voltages do in a series ac circuit. Brush up on your ac theory and see if you can solve the missing voltage or current in the circuits below. Where necessary, the voltages and currents are related by the 3:4:5 ratio to provide easy, whole number answers. Only simple algebra is required. Vectors, phasors, and quadratic equations are not necessary to find the solutions.

(See answers below)

AC Circuit Theory Quiz - RF Cafe
AC Circuit Theory Quiz


















Circuit Quiz Answers

1. (10)2 = (8)2 + (VR)2; VR = 6V

2. (20)
2 = (7+VC)2 + (12)2; VC = 9V

3. (24)
2 = (VL-6)2; VL = 30V

4. (15)
2 = (350-350)2 + (VR)2; VR = 15V

5. (VT)
2 = (15-3)2 + (16)2; VT = 20V

6. (50)
2 = (VL)2 + (12)2 = (VC)2 + (12)2; VL = VC

    (VT)
2 = (VL-VC)2 + (12)2; VT = 12V

7. (IT)
2 = (6)2 + (8)2; IT = 10 mA.

8. (20)
2 = (16-IC)2 + (16)2; IC = 4 mA.

9. (IT)
2 = (17-13)2 + (3)2; IT = 5 mA.

10. (9)
2 = (40-4-IC)2; IC = 7 mA.




Posted  6/21/2013

A Disruptive Web Presence

Custom Search
Over 10,000 pages indexed! (none duped or pirated)

Read About RF Cafe
Webmaster: Kirt Blattenberger
    KB3UON

RF Cafe Software

RF Cascade Workbook
RF Cascade Workbook is a very extensive system cascaded component Excel workbook that includes the standard Gain, NF, IP2, IP3, Psat calculations, input & output VSWR, noise BW, min/max tolerance, DC power cauculations, graphing of all RF parameters, and has a graphical block diagram tool. An extensive User's Guide is also included. - Only $35.
RF system analysis including
frequency conversion & filters

RF & EE Symbols Word
RF Stencils for Visio

Product & Service Directory
Personally Selected Manufacturers
RF Cafe T-Shirts & Mugs

RF Cafe Software

Calculator Workbook
RF Workbench
Smith Chart™ for Visio
Smith Chart™ for Excel
Your RF Cafe Progenitor & Webmaster
Click here to read about RF CafeKirt Blattenberger... single-handedly redefining what an
                                 engineering website should be.

View the YouTube RF Cafe Intro Video Carpe Diem! (Seize the Day!)

5CCG (5th MOB): My USAF radar shop

Airplanes and Rockets: My personal hobby website

Equine Kingdom: My daughter Sally's horse riding website