June 1963 Popular Electronics
Wax nostalgic about and learn from the history of early electronics. See articles
published October 1954 - April 1985. All copyrights are hereby acknowledged.
Having worked around resistors
and capacitors for more than four decades comes in handy when presented with 'simple'
quizzes like this one that appeared in a 1963 Popular Electronics dealing
with RC circuits. Still, there is always some trepidation involved when being subject,
even voluntarily, to a test of any sort, regardless of whether you are fairly confident
that it will be a lead pipe cinch, a cake walk, child's play, so to speak. Even
if nobody else will bear witness to your effort, you would feel like a real moron
if you missed even one of those simple questions that anyone with your level of
experience should get right without even having to think about it. Such is the irrational
fear I have when taking these quizzes prior to posting them on RF Cafe. I have always
been honest about the results, and there have been instances where I missed a couple
that I shouldn't have by all rights (or wrongs). This time, however, Lady Luck was
with me and I aced it. If you're not accustomed to seeing those strange round schematic
symbols with a mix of solid and dashed horizontal lines within, those are vacuum
tubes. Just mentally substitute your favorite solid state amplifier like a bipolar
of a field effect transistor.
RC Circuit Quiz
By Robert P. Balin
Circuits that are made up of resistors and capacitors only perform a wide variety
of functions in electronic equipment. Try to match the RC circuit functions listed
(1-10) with the circuits (A-J) to which they apply.
Answers are at the bottom of the page.
1 Decoupling network ____
2 Treble-cut tone control ____
3 Differentiator ____
4 Frequency control ____
5 Phase-shifting network ____
6 Timing control ____
7 Equalizer ____
8 Integrator ____
9 Band suppression filter ____
10 RC coupling circuit ____
Popular Electronics published many quizzes over the years
- some really simple and others not so simple. Robert Balin created many of the quizzes.
This is a listing of all I have posted thus far.
- Electronics IQ Quiz
- May 1967
- Plug and Jack Quiz
- December 1967
Switching Quiz - October 1967
Angle Quiz - September 1967
Electronics Quiz - July 1967
- Bridge Circuit
Quiz -December 1966
- Diode Function
Quiz - August 1965
- Diagram Quiz, August
- TV Trouble Quiz,
- Electronics History Quiz,
- Scope-Trace Quiz,
Circuit Analogy Quiz, April 1973
Your Knowledge of Semiconductors, August 1972
- Ganged Switching
Quiz, April 1972
- Lamp Brightness
Quiz, January 1969
- Lissajous Pattern Quiz, September 1963
Quizoo, October 1962
- Electronic Photo Album Quiz, March 1963
- Electronic Alphabet Quiz, May 1963
- Quiz: Resistive?
Inductive? or Capacitive?, October 1960
- Vector-Circuit Matching Quiz, June 1970
Quiz, September 1961
- RC Circuit
Quiz, June 1963
- Diode Quiz,
- Electronic Curves Quiz, February 1963
- Electronic Numbers Quiz, December 1962
- Energy Conversion Quiz, April 1963
Function Quiz, June 1962
Quiz - February 1967
- Unknown Frequency
Quiz - September 1965
Metals Quiz - October 1964
Measurement Quiz - August 1967
- Meter-Reading Quiz,
Geometry Quiz, January 1965
Factor Quiz, November 1966
Math Quiz, November 1965
- Series Circuit Quiz,
Quiz, March 1966
- Electronic Analogy
Quiz, November 1961
Coupling Quiz, August 1973
- Electronics Analogy Quiz, August 1960
- Audio Quiz,
Unit Quiz, May 1962
Capacitor Circuit Quiz, June 1968
- Quiz on AC Circuit Theory, December 1970
- Magnetic Phenomena Quiz, February 1962
- Electronics Geography Quiz, April 1970
Electronic Menu Quiz, August 1963
- Electronic Noise Quiz, August 1962
- Electronic Current Quiz, October 1963
- Electronic Inventors Quiz, November 1963
Function Quiz, January 1962
- Electronic Measurement Quiz, January 1963
Tube Quiz, February 1961
- Kool-Keeping Kwiz, June
RC Circuit Quiz Answers
1 - D - A Decoupling Network acts as a low-pass filter so that signal frequencies
are bypassed to ground
and not coupled to other stages via the power supply.
2 - A - A Treble-cut Tone Control in the plate circuit of an audio amplifier
acts as a low-pass filter. Decreasing
the amount of resistance bypasses an increasing amount of the highs to ground.
3 - G - A Differentiator is a high-pass filter which removes low-frequency components
of a square wave.
Capacitor charges very quickly and permits only short pulses of current through
4 - J - The Frequency Control circuit for this blocking oscillator biases the
transistor to cutoff until the capacitor
has discharged through the resistor. The capacitor then charges up again through
the transistor when
begins to conduct.
5 - F - The Phase-Shifting Network to provide in-phase (positive) feedback for
this oscillator consists of three
cascaded RC circuits, The voltage across each resistor leads the signal applied
to each RC section
by 60 degrees.
6 - E - The Timing Control for this time delay circuit is an RC circuit which
controls the transistor emitter-base
biasing. The relay remains energized until the capacitor is charged and opposes
the forward bias
provided by the battery.
7 - I - An Equalizer for a crystal phonograph cartridge is a low-pass filter
designed to compensate for the
attenuation of low frequencies in disc recordings.
8 - B - An Integrator is a low-pass filter which removes high frequencies from
a square wave, In this
long-time-constant circuit, the capacitor charges and discharges slowly through
9 - C - A Band Suppression Filter such as this Wien bridge contains both series
and parallel RC circuits which
balance with the resistive arms to null the output signal at a particular frequency.
10 - H - An RC Coupling Circuit is really a form of high-pass filter; capacitor
must be large enough in proportion
to resistor to pass the lowest signal frequency without excessive attenuation.
Posted July 2, 2019