Online courses for the ham radio license exams. The QSO Radio Show

Extra Class Exam Question Pool

effective 7/01/2016 thru 6/29/2020

    Unseen questions
    Weak questions
    Review questions
    Learned questions
    Incorrect answer choices  

2016-E6F: Optical components: photoconductive principles and effects, photovoltaic systems, optical couplers, optical sensors, and optoisolators; LCDs

2016-E6F01: What is photoconductivity?

The increased conductivity of an illuminated semiconductor

The conversion of photon energy to electromotive energy

The conversion of electromotive energy to photon energy

The decreased conductivity of an illuminated semiconductor

2016-E6F02: What happens to the conductivity of a photoconductive material when light shines on it?

It increases

It decreases

It stays the same

It becomes unstable

2016-E6F03: What is the most common configuration of an optoisolator or optocoupler?

An LED and a phototransistor

A lens and a photomultiplier

A frequency modulated helium-neon laser

An amplitude modulated helium-neon laser

2016-E6F04: What is the photovoltaic effect?

The conversion of light to electrical energy

The conversion of voltage to current when exposed to light

The conversion of electrical energy to mechanical energy

The tendency of a battery to discharge when used outside

2016-E6F05: Which describes an optical shaft encoder?

A device which detects rotation of a control by interrupting a light source with a patterned wheel

A device which measures the strength of a beam of light using analog to digital conversion

A digital encryption device often used to encrypt spacecraft control signals

A device for generating RTTY signals by means of a rotating light source

2016-E6F06: Which of these materials is affected the most by photoconductivity?

A crystalline semiconductor

An ordinary metal

A heavy metal

A liquid semiconductor

2016-E6F07: What is a solid state relay?

A device that uses semiconductors to implement the functions of an electromechanical relay

A relay using transistors to drive the relay coil

A mechanical relay that latches in the on or off state each time it is pulsed

A passive delay line

2016-E6F08: Why are optoisolators often used in conjunction with solid state circuits when switching 120VAC?

Optoisolators provide a very high degree of electrical isolation between a control circuit and the circuit being switched

Optoisolators provide a low impedance link between a control circuit and a power circuit

Optoisolators provide impedance matching between the control circuit and power circuit

Optoisolators eliminate the effects of reflected light in the control circuit

2016-E6F09: What is the efficiency of a photovoltaic cell?

The relative fraction of light that is converted to current

The output RF power divided by the input DC power

The effective payback period

The open-circuit voltage divided by the short-circuit current under full illumination

2016-E6F10: What is the most common type of photovoltaic cell used for electrical power generation?



Cadmium Sulfide

Copper oxide

2016-E6F11: What is the approximate open-circuit voltage produced by a fully-illuminated silicon photovoltaic cell?

0.5 V

0.1 V

1.5 V

12 V

2016-E6F12: What absorbs the energy from light falling on a photovoltaic cell?





2016-E6F13: What is a liquid crystal display (LCD)?

A display utilizing a crystalline liquid and polarizing filters which becomes opaque when voltage is applied

A modern replacement for a quartz crystal oscillator which displays its fundamental frequency

A frequency-determining unit for a transmitter or receiver

A display that uses a glowing liquid to remain brightly lit in dim light

2016-E6F14: Which of the following is true of LCD displays?

They may be hard view through polarized lenses

They are hard to view in high ambient light conditions

They only display alphanumeric symbols

All of these choices are correct

Color key:
● = Unseen
● = Weak
● = Review
● = Learned
● = Incorrect answer
Previous group:
2016-E6E: Analog ICs: MMICs, CCDs, Device packages
Back to index:
Extra Class Exam Question Pool
Next group:
2016-E7A: Digital circuits: digital circuit principles and logic circuits: classes of logic elements; positive and negative logic; frequency dividers; truth tables
Home     What is ham radio?     Which exam to take?     Study tips     Where to take the exam?     Frequency Asked Questions (FAQ)     How to     How much math?     Trouble with practice exams     Feedback     Prices     Ham It Forward     Free Extra course for active volunteer examiners     Refund policy     Privacy policy    Terms and conditions     Bumper sticker     Advertise with us     The Ham band     Rate us     Question pools     Course structure     Survivalists     Documents     facebook     Google+     Contact us     Christina's story     TestOnline     Links

The best study method, customer support, and guarantee in the industry!

A TestOnline website.  Copyright © 1998-, HamTestOnline™.  All rights reserved.