Wax nostalgic about and learn from the history of early electronics. See articles
from Popular Electronics,
published October 1954 - April 1985. All copyrights are hereby acknowledged.
Thank God It's Friday (TGIF)
once again. I keep looking back through issues of Popular Electronics magazine
for Robert Balin quizzes that I might have missed, and fortunately this one was found.
Unlike quizzes back in school, nobody but you will ever know how you score on it - that's
what makes it fun. Your challenge is to determine the total resistance value between
points A and B both before and after inserting the plug into the jack. Mercifully, Mr. Balin
specifies that all the resistors are the same value. The Before part is a piece of cake
even for someone in a first semester electronics course - just be sure to pay attention
to whether or not the contacts short out any of the paths. The phono plug is on the left
and the corresponding jack is on the right. Interpret the dual resistors plug circuits
in figures 5 through 8 as having one resistor connected to the tip contact and the other
resistor connected to the ring contact (see drawing below), so each connects individually
to the upper and lower contacts when inserted into its jack.
Plug and Jack Quiz
By Robert P. Balin
Plugs and jacks are used not only to connect various units of electronic equipment
together, but also to perform a variety of switching operations at the same time. To
test your ability to analyze plug and jack connections, sharpen your pencil and try working
the circuit problems (1-8) shown below. Determine the total equivalent resistance between
points A and B in each circuit Before and After the plug is inserted in the jack. All
of the resistors are 6-ohm units.
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.
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