Electronics World articles Popular Electronics articles QST articles Radio & TV News articles Radio-Craft articles Radio-Electronics articles Short Wave Craft articles Wireless World articles Google Search of RF Cafe website Sitemap Electronics Equations Mathematics Equations Equations physics Manufacturers & distributors Engineer Jobs LinkedIn Crosswords Engineering Humor Kirt's Cogitations Engineering Event Calendar RF Engineering Quizzes USAF radar shop Notable Quotes App Notes Calculators Education Engineering Magazines Engineering magazine articles Engineering software Engineering smorgasbord RF Cafe Archives RF Cascade Workbook 2018 RF Stencils for Visio RF & EE Shapes for Word Advertising RF Cafe Homepage Sudoku puzzles Thank you for visiting RF Cafe!
Innovative Power Products Resistors

Ultra Low Power Bioelectronics
Answers to RF Cafe Quiz #24

RF Engineering Quizzes - RF CafeAll RF Cafe quizzes make great fodder for employment interviews for technicians or engineers - particularly those who are fresh out of school or are relatively new to the work world. Come to think of it, they would make equally excellent study material for the same persons who are going to be interviewed for a job.

Click here for the complete list of RF Cafe Quizzes.

Note: Some material based on books have quoted passages.

Return to RF Cafe Quiz #24

RF Cafe Featured Book - Ultra Low Power Bioelectronics: Fundamentals, Biomedical Applications, and Bio-inspired SystemsThis quiz is based on the information presented in Ultra Low Power Bioelectronics: Fundamentals, Biomedical Applications, and Bio-Inspired Systems, by Rahul Sarpeshkar, published by Cambridge University Press.
 Note: Some of these books are available as prizes in the monthly RF Cafe Giveaway.

RF Cafe - Quiz #24, 1/f noise1.  Which formula represents what is known as "1/f" noise?

b)  1/fn

Noise has many sources, including thermal. flicker, 1/f, etc. The 1/f component dominates in the region from DC to the point where 1/f noise is equal to white noise power (fc).
An explanation, along with the chart to the right, is from page 170.

2.  What is Return Ratio Analysis?

b)  A method for analyzing circuit robustness in response to changes in gain or impedance

Return ratio is a quantity analogous to the robustness of a transmission feedback loop, in that its analysis quantifies the robustness of a circuit in response to a change in gain or impedance.
An explanation is given in chapter 10 (p 240).

RF Cafe - Quiz #24, Middlebrook's extra element theorem3.  What is the name of the process used to simplify
     analysis of a complex system when an additional
     passive element is added in parallel?

c)  Middlebrook's extra-element theorem

This approach defines how to simplify analyzing a complex system (for which a transfer function is known) when a passive element is added in parallel or in series to it.
An explanation is given on page 261.

4.  What function does a gyrator circuit perform?

a)  Inverts impedance (changes L to C, or C to L)

This is an Electronics 101 circuit that uses a one or more active elements to basically switch the sign of the imaginary part of a complex impedance.
An explanation is given on page 333.

5.  What is a key feature of a neuron-inspired analog-to-digital converter?

a)  Brain-like logic
b)  Small size comparable to neurons
c)  A concept though of while using the inventor's brain's neurons
d)  Energy efficiency

Just as the biological brain is an extremely efficient processor of information, a properly configured ADC circuit can gain enhanced efficiency.
An explanation is given on page 395.

6.  What does the Bode-Fano criterion state?

d)  For passive loads (series or parallel RC or RL), there is an inverse relationship between good
     impedance matching at a single frequency and good matching across the entire band

This is intuitive to anyone who has struggled to find a good impedance match across a wide bandwidth using a minimum number of elements.
An explanation is given on page 471.

7.  Which type of biomedical implant is not likely to employ a wireless link to an external transceiver?

c)  Hair plug

Many kinds of medical implants exploit the availability of micro-scale wireless electronics to both retrieve data from implants and to send programming data to them.
An explanation is given on page 395.

RF Cafe - Quiz #24, Biological skin depth chart8.  Which curve in the graph to the right represents
     skin depth in biological tissue?

b)  A

RF Cafe - Quiz #24, Biological skin depth equivalent circuitTo the left is a transmission line model of biological tissue that helps predict how an RF plane wave propagates through tissues.

Component values vary with frequency and tissue type.

An explanation is given on page 526.

9.  What is the approximate power consumed by the average
     human male brain, consisting of 22 billion neuronal cells?

b)  15 W

Oh, the jokes that can come from this question! It has been estimated that the human brain performs the equivalent of at least 6x1016 FLOPS (floating-point operations per second) while consuming a mere 15 W of power.
An explanation is given on page 395.

RF Cafe - Quiz #24, Current-dependent battery polarization10.  Name the three regions of current-dependent battery polarization as a function of voltage

a)  Active, ohmic, concentration

An explanation, along with the chart to the right, is from page 801.
Triad RF Systems PCB Directory (Design)
Axiom Test Equipment - RF Cafe
About RF Cafe
Kirt Blattenberger - RF Cafe Webmaster
Copyright: 1996 - 2024
    Kirt Blattenberger,

RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The World Wide Web (Internet) was largely an unknown entity at the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps while typing up your telephone line, and a nice lady's voice announced "You've Got Mail" when a new message arrived...

All trademarks, copyrights, patents, and other rights of ownership to images and text used on the RF Cafe website are hereby acknowledged.

My Hobby Website:  AirplanesAndRockets.com


Please Support RF Cafe by purchasing my  ridiculously low−priced products, all of which I created.

These Are Available for Free