Electronic Current Quiz
October 1963 Popular Electronics
This Electronics Current
Quiz from the October 1963 edition of Popular Electronics is recent enough (if you can consider 50 years ago) that
it uses both transistors as well as vacuum tubes in the example circuits. I have to admit to only scoring 60% on
it, which is pretty lame. You will probably do better, especially if you are my age or older.
[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. As time permits, I will be glad to scan articles for you. All copyrights (if any) are hereby acknowledged.
See all articles from Popular
Electronic Current Quiz
By Robert P. Balin
fact that any electric current is a movement of electric charges, a variety of odd names have been devised for currents
that operate specific electronic circuits or parts. See if you can match each special current name (A-J) listed below
with the circuit of the component (1-10) to which it relates.
A Pull-in current ___
B Exciting current ___
C Bleeder current ___
D Eddy current ___
E Dark current ___
F Bias current ___
G Leading current ___
H Leakage current ___
Field current ___
J Beam current ___
Current Quiz Answers
A - 10 The PULL-IN current for a relay is the minimum coil
current that will move the armature to the closed position.
B - 6 The EXCITING current in a transformer
is the primary current which flows when the secondary winding is open.
C - 3 A BLEEDER current, usually
about 10% of the rated output current, flows in the bleeder resistor of a power supply, and improves the regulation
of the output voltage.
D - 5 EDDY currents are induced in the work piece by transformer action in the r.f.
induction heating process.
E - 4 The DARK current in a photoelectric tube is the current which flows in the
absence of light.
F - 2 The d.c, BIAS current in a transistor common-emitter circuit determines the operating
point for the signal current.
G - 8 A LEADING current is present in a capacitive circuit because of the current
surges into the capacitor.
H - 9 The LEAKAGE current, or Iceo in a transistor, is the collector
current which flows with zero base current.
I - 7 The FIELD current is the current that energizes the electromagnet
of an electrodynamic loudspeaker. It is often obtained by using the field coil as the choke in the amplifier power
J - 1 The BEAM current in a cathode-ray tube is the electron stream which is accelerated toward the
fluorescent screen .