April 1967 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.
Here is a quick test of your graph
reading skills. It appeared in the April 1967 edition of Popular Electronics. I missed
#6 - a temporary (hopefully) case of cranial rectumitis on my part. Maybe you will do
Graph Interpretation Quiz
By Robert P. Balin
Today's front-line electronic technician must be able to interpret readily the various
charts and graphs devised by engineers to convey important information on the electrical
characteristics of circuits as well as of individual components. In addition, the technician
must be thoroughly familiar with the origin and composition of a variety of unusual as
well as standard oscillographic waveforms. Test your ability to interpret the graphs
and waveforms shown below (1-10) by selecting the most likely meaning, (A) or (B), from
the two possibilities given in each case.
1. The family of plate characteristic curves for a triode shows
that as the plate voltage is increased the a.c. plate resistance (A) increases or (B)
2. The distortion seen in this square-wave test signal indicates
that the amplifier being tested is attenuating the (A) low frequencies or (B) high frequencies.
3. The collector current vs. base current curve for a transistor
indicates that as the base current is increased the beta (gain) of the transistor (A)
increases or (B) decreases.
4. This transmitter modulation pattern indicates that the r.f.
carrier is (A) over-modulated or (B) under-modulated
5. Output curves show that as a transistor's collector voltage
increases, the a.c. output resistance (A) increases or (B) decreases.
6. Vacuum-tube mutual transconductance curve indicates that
as grid bias is increased mutual transconductance, Gm, (A) increases or (B) decreases.
7. Of the two load lines, (A) and (B), shown in the graph at
right, which one represents the larger value of load resistance?
8. The magnetization curve for a transformer core material shows
that as the core goes into saturation its permeability (A) increases or (B) decreases.
9. The rate of change of a current depicted by a sine wave is
greatest when the current is at its peak (A), or (B) when it is passing through 0.
10. This frequency response curve for a tuned transformer indicates
that the windings are (A) over-coupled or (B) under-coupled.
See answers below.
Quizzes from vintage electronics magazines such as Popular
Electronics, Electronics-World, QST, and Radio News were published
over the years - some really simple and others not so simple. Robert P. Balin
created most of the quizzes for Popular Electronics. This is a listing
of all I have posted thus far.
Radio Quiz - December 1947 Radio-Craft
Quiz - October 1955 Radio & Television News
- Electronics Physics
Quiz - March 1974 Popular Electronics
- A Baffling Quiz
- January 1968 Popular Electronics
- Electronics IQ
Quiz - May 1967 Popular Electronics
- Plug and Jack
Quiz - December 1967 Popular Electronics
Switching Quiz - October 1967 Popular Electronics
Angle Quiz - September 1967 Popular Electronics
Electronics Quiz - July 1967 Popular Electronics
- FM Radio
Quiz - April 1950 Radio & Television News
- Bridge Circuit
Quiz -December 1966 Popular Electronics
- Diode Function
Quiz - August 1965 Popular Electronics
- Diagram Quiz,
August 1966 Popular Electronics
- Quist Quiz - November
- TV Trouble Quiz,
July 1966 Popular Electronics
- Electronics History Quiz,
December 1965 Popular Electronics
- Scope-Trace Quiz,
March 1965 Popular Electronics
Circuit Analogy Quiz, April 1973
Test Your Knowledge of Semiconductors, August 1972 Popular Electronics
- Ganged Switching
Quiz, April 1972 Popular Electronics
- Lamp Brightness
Quiz, January 1969 Popular Electronics
- Lissajous Pattern Quiz, September 1963 Popular Electronics
Quizoo, October 1962 Popular Electronics
- Electronic Photo Album Quiz, March 1963 Popular Electronics
- Electronic Alphabet Quiz, May 1963 Popular Electronics
- Quiz: Resistive?
Inductive? or Capacitive?, October 1960 Popular Electronics
- Vector-Circuit Matching Quiz, June 1970 Popular Electronics
Quiz, September 1961 Popular Electronics
- RC Circuit Quiz,
June 1963 Popular Electronics
- Diode Quiz, July
1961 Popular Electronics
- Electronic Curves Quiz, February 1963 Popular Electronics
- Electronic Numbers Quiz, December 1962 Popular Electronics
- Energy Conversion Quiz, April 1963 Popular Electronics
- Coil Function
Quiz, June 1962 Popular Electronics
Co-Inventors Quiz - January 1965 Electronics World
"-Tron" Teasers Quiz - October 1963 Electronics World
- Polarity Quiz
- March 1968 Popular Electronics
I.Q. Quiz - October 1948 Radio & Television News
- Amplifier Quiz
Part I - February 1964 Popular Electronics
Quiz - February 1967 Popular Electronics
Frequency Quiz - September 1965 Popular Electronics
Metals Quiz - October 1964 Popular Electronics
Measurement Quiz - August 1967 Popular Electronics
Quiz, June 1966 Popular Electronics
Geometry Quiz, January 1965 Popular Electronics
Factor Quiz, November 1966 Popular Electronics
Math Quiz, November 1965 Popular Electronics
- Series Circuit
Quiz, May 1966 Popular Electronics
Quiz, March 1966 Popular Electronics
Quiz: Test Your Sales Ability - April 1947 Radio News
Analogy Quiz, November 1961 Popular Electronics
Coupling Quiz, August 1973 Popular Electronics
- Electronics Analogy Quiz, August 1960 Popular Electronics
- Audio Quiz, April
1955 Popular Electronics
- Electronic Unit
Quiz, May 1962 Popular Electronics
Circuit Quiz, June 1968 Popular Electronics
- Quiz on AC Circuit Theory, December 1970 Popular Electronics
- Magnetic Phenomena Quiz, February 1962 Popular Electronics
- Electronics Geography Quiz, April 1970 Popular Electronics
Menu Quiz, August 1963 Popular Electronics
- Electronic Noise Quiz, August 1962 Popular Electronics
- Electronic Current Quiz, October 1963 Popular Electronics
- Electronic Inventors Quiz, November 1963 Popular Electronics
- Resistor Function
Quiz, January 1962 Popular Electronics
- Electronic Measurement Quiz, January 1963 Popular Electronics
- Vacuum Tube Quiz,
February 1961 Popular Electronics
- Kool-Keeping Kwiz, June
1970 Popular Electronics
- Find the Brightest
Bulb Quiz, April 1960 Popular Electronics
Where Do the Scientists Belong? - Feb 19, 1949 Saturday Evening
1 - B The slope of these curves represents the ratio Ip/Ep,
or conductance (the reciprocal of resistance). As the plate voltage is increased, the
slope and conductance also increase, and the resistance decreases.
2 - A The fundamental and low-frequency components of a square wave contribute chiefly
to the center portion of its flat top. Thus, if an amplifier under test attenuates the
low frequencies, a dip appears in the center of the square-wave test signal.
3 - B The slope of this curve represents the ratio lc/IB, or
beta, the current gain of a transistor. As the base current increases, the slope of the
curve and beta decrease.
4 - A Overmodulation can reduce an r.f. carrier to zero amplitude during a period
of time as shown by the thin base line through the modulation envelope.
5 - A The slope of this family of curves indicates changes in the conductance of the
transistor. As the collector voltage (VCE) is increased, the slope and conductance
decrease, and the resistance increases.
6 - B The slope of this curve represents the ratio Ip/EG, or
mutual conductance (Gm) of this vacuum tube. As the grid voltage (Eg) is increased,
the slope and Gm decrease.
7 - B The slope of a load line represents the conductance of the load resistance.
The load line with the lesser slope (B) shows a lower conductance, or higher resistance.
8 - B The slope of this curve reflects the ratio B/H, the permeability of the core
material. As the curve goes over the knee, the slope and permeability both decrease.
9 - B At its peak amplitude, a sine wave changes from one finite value to another,
but as it passes through zero it changes from a finite value to zero, resulting in an
infinite percent change.
10 - A When the windings of a tuned air-core transformer are overcoupled, a dip is
produced in the center of an otherwise single-peaked frequency-response curve, and two
new resonant peaks occur at slightly higher and lower frequencies.
Posted July 26, 2012