Amateur Radio Quiz: The Ins-and-Outs of the Bits-and-Pieces


By H. Ward Silver, N0AX

Once the homebuilding bug bites, you’ll be using a whole new set of jargon: acronyms, color codes, numbering conventions, parameters, measurements and more. Here are some questions about the many interesting methods -- and short-cuts -- we use to describe our electronic components.

1) Which sequence represents the resistor color code?

2) The frequency at which an inductor’s inductance and parasitic capacitance have equal reactance is the ______________ frequency.
a) self-resonant
b) self-tuned
c) self-excited
d) maximum useable

3) If a resistor has a positive temperature coefficient, what happens when it gets hot?
a) Its resistance increases.
b) The tolerance of the resistor gets tighter.
c) Air flow around it becomes turbulent.
d) Its voltage drop decreases.

4) DIP stands for what?
a) Dual Integrated Placement
b) Destructive Immolation Probability
c) Dual In-Line Package
d) Differential Integrity Profile

5) Which temperature coefficient abbreviation indicates that a capacitor value is stable around room temperature?
a) Z5U
b) X7Z
c) NPO
d) NCO

6) Match the resistor type with its distinguishing characteristic
a) wire-wound          e) inexpensive
b) metal oxide            f) high power dissipation
c) metal film               g) non-inductive
d) carbon film            h) low noise

7) Which type of inductor core is most often used in switching-type power supplies?
a) ferrite
b) laminated steel
c) air
d) epoxy

8) Which of the following in not a common transistor packaging type?
a) TO-220
b) SOT
c) TO-92
d) FFT

9) Rank the following diode types in order of forward voltage drop for a given current.
a) Schottky barrier
b) Germanium
c) Silicon
d) Selenium

10) Match the type of capacitor with its distinguishing characteristic.
a) ceramic              d) high capacity
b) silvered mica     e) low loss at RF
c) electrolytic         f) inexpensive

11) Which type of component can be “slug-tuned?”
a) capacitor
b) resistor
c) inductor

12) Which of these abbreviations are equivalent?
a) µF
b) µµF
c) nF
d) pF

13) What does a gold tolerance band in the resistor four-band color code mean?
a) 1 percent
b) 5 percent
c) 10 percent
d) 20 percent

14) Which of the following lead markings indicates that a transistor is an FET?
a) EBC
b) PIE
c) SGD
d) VCC

15) Which parameter determines the voltage ratio between a transformer's primary and secondary windings?
a) mutual coupling
b) stand-off voltage
c) volts-per-turn
d) turns ratio

Bonus: A “slop jar” does what to alternating current?



1. b -- Black/Brown/Red/Orange/Yellow/Green/Blue/Violet/Gray/White. Answer (a) is the sequence of stellar spectral classifications and answer (c) is the lines in the treble staff. Answer (d) means “Pay No Attention To That Man Behind The Curtain.”
2. a -- At this frequency an inductor can appear to be an open or short circuit!
3. a -- Resistance of nearly all materials increases with temperature.
4. c
5. c
6. a-f, b-g, c-h, d-e
7. a -- Ferrites offer low-loss and high-permeability at audio and higher frequencies.
8. d -- TO-220 and TO-92 are common plastic packages and SOT stands for Small Outline Transistor for surface-mount parts.
9. a-b-c-d lowest to highest
10. a-f, b-e, c-d
11. c
12. b and d -- Before the term pico came into wide use, micro-micro was the usual value prefix.
13. b -- In the four-band color code system, silver indicates 10 percent and no tolerance band means 20 percent.
14. c -- SGD stands for Source-Gate-Drain
15. d

Bonus: A “slop jar” rectifies the alternating current. Slop jar rectifiers -- consisting of two strips of metal in an electrolyte solution -- were common before selenium and vacuum-tube rectifiers became widely available.