What did Heinrich Hertz discover in 1888?
- The existence of electromagnetic radiation
- The ability of metal filings to cohere when exposed to electric waves
- The use of a spark gap to generate electric waves
- The ability of vacuum tubes to amplify radio signals
Correct Answer: The existence of electromagnetic radiation
Correct Answer Explanation: Heinrich Hertz’s experiments in 1888 demonstrated that the spark of an induction coil creates electric oscillations in an open circuit, and that these oscillations can be transmitted as electric waves, which are now known as electromagnetic radiation.
What year did William Marconi invent the wireless telegraph?
- 1890
- 1895
- 1896
- 1899
Correct Answer: 1896
Correct Answer Explanation: William Marconi’s invention of the wireless telegraph in 1896 marked a pivotal moment in the development of radio communication. He initially transmitted dot and dash signals over a distance of 200-300 feet.
Who invented the wireless telephone?
- Heinrich Hertz
- William Marconi
- A. Frederick Collins
- Sir Oliver Lodge
Correct Answer: A. Frederick Collins
Correct Answer Explanation: A. Frederick Collins, the author of the 1922 Radio Amateur’s Handbook, invented the wireless telephone in 1899. His first experiments successfully transmitted the human voice over a distance of three blocks.
What device did Edward Branly demonstrate in 1890?
- A vacuum tube detector
- A coherer
- A spark gap
- A magnetic modulator
Correct Answer: A coherer
Correct Answer Explanation: Edward Branly’s 1890 demonstration of a device called a radio conductor, which used metal filings in a tube that cohered when exposed to electric waves, was an important step in the development of radio receivers. Sir Oliver Lodge later improved upon this device, calling it a coherer.
What year did Alexander Popoff build a receiving set for studying atmospheric electricity?
- 1890
- 1895
- 1896
- 1899
Correct Answer: 1895
Correct Answer Explanation: Alexander Popoff’s 1895 creation of a receiving set for studying atmospheric electricity demonstrated the earliest recorded use of a detector connected to an aerial and the earth. This pioneering work laid the foundation for future wireless communication systems.
What was the primary limitation of spark gaps for wireless telephony?
- They produced damped oscillations.
- They were too expensive to produce.
- They were too complex to operate.
- They were too inefficient to transmit speech.
Correct Answer: They produced damped oscillations.
Correct Answer Explanation: Spark gaps produce damped, periodic oscillations that are unsuitable for transmitting speech, which requires sustained, continuous oscillations. Arc lights and vacuum tubes were later developed to produce these necessary continuous oscillations.
Who invented the vacuum tube detector in 1905?
- A. Frederick Collins
- J. A. Fleming
- Heinrich Hertz
- William Marconi
Correct Answer: J. A. Fleming
Correct Answer Explanation: In 1905, J. A. Fleming, an English physicist, invented the vacuum tube detector, which was later perfected and found to act as an amplifier as well, revolutionizing radio technology.
How did vacuum tubes revolutionize radio communication?
- They provided a way to amplify and generate sustained oscillations.
- They allowed for the development of more compact transmitters.
- They enabled the transmission of speech and music over longer distances.
- All of the above
Correct Answer: All of the above
Correct Answer Explanation: Vacuum tubes provided a crucial breakthrough in radio communication by enabling the amplification and generation of sustained oscillations, necessary for transmitting speech and music, and by allowing for the development of more compact and powerful transmitters.
What was the primary method of communication in amateur radio during the early 20th century?
- Speech
- Morse code
- Telegraphy
- All of the above
Correct Answer: Morse code
Correct Answer Explanation: In the early days of amateur radio, Morse code was the primary method of communication, as transmitting speech was challenging due to the complexity and cost of arc-based transmitters.
What government agency regulates amateur radio in the United States?
- The Federal Communications Commission (FCC)
- The National Institute of Standards and Technology (NIST)
- The National Aeronautics and Space Administration (NASA)
- The Department of Defense (DoD)
Correct Answer: The Federal Communications Commission (FCC)
Correct Answer Explanation: The FCC is responsible for regulating all forms of radio communication in the United States, including amateur radio. They issue licenses and set regulations for amateur radio operators.
What was the primary impact of World War I on radio technology?
- It led to the development of the vacuum tube.
- It spurred significant advancements in radio technology.
- It led to the invention of the wireless telegraph.
- It led to the widespread adoption of amateur radio.
Correct Answer: It spurred significant advancements in radio technology.
Correct Answer Explanation: World War I’s demand for reliable and advanced radio communication for military purposes led to significant breakthroughs in the field, with advancements in both hardware and software, including the development of more powerful transmitters, better receivers, and more sophisticated coding systems.
What did the emergence of radio broadcasting change about radio communication?
- It shifted from primarily code-based messages to the transmission of music, talks, and news programs.
- It made radio technology more accessible to the general public.
- It led to the development of the vacuum tube.
- It spurred significant advancements in radio technology.
Correct Answer: It shifted from primarily code-based messages to the transmission of music, talks, and news programs.
Correct Answer Explanation: The emergence of radio broadcasting in the early 20th century transformed radio communication from primarily code-based messages to the transmission of music, talks, and news programs, making radio a more entertaining and informative medium for the public.
What did A. Frederick Collins predict as the future of radio communication?
- The use of radio for diverse applications like weather reports, crop information, time signals, and even political speeches and religious sermons.
- The widespread adoption of amateur radio.
- The development of the vacuum tube.
- The invention of television.
Correct Answer: The use of radio for diverse applications like weather reports, crop information, time signals, and even political speeches and religious sermons.
Correct Answer Explanation: A. Frederick Collins, with his visionary outlook, anticipated the broad range of applications for radio communication, envisioning its use for various purposes beyond simple communication, such as disseminating information about weather, agriculture, and even political and religious matters.
How was radio technology being used in transportation in the early 20th century?
- Communication between moving trains and automobiles
- Remote control of motor cars
- Navigation systems for ships and airplanes
- All of the above
Correct Answer: All of the above
Correct Answer Explanation: Radio technology was rapidly being adopted in transportation during the early 20th century, with applications ranging from communication between moving trains and automobiles to remote control of motor cars and even navigation systems for ships and airplanes.
What did the emergence of wireless colleges indicate about the growing importance of radio communication?
- The growing importance of radio communication in society
- The growing demand for skilled radio operators
- The growing investment in radio technology education
- All of the above
Correct Answer: All of the above
Correct Answer Explanation: The establishment of wireless colleges at universities like Tufts, Hunter, Princeton, Yale, Harvard, and Columbia demonstrated the growing recognition of radio communication as a vital field, leading to a surge in demand for skilled operators and investment in educational programs to train them.
What was the ratio of amateur receiving stations to sending stations in the United States in 1922?
- 1:1
- 2:1
- 5:1
- 15:1
Correct Answer: 15:1
Correct Answer Explanation: The prevalence of amateur receiving stations compared to sending stations in the United States in 1922, with a ratio of 15:1, indicates the strong interest in listening to radio signals and the growing popularity of amateur radio, even though building and operating transmitting sets was more challenging and expensive.
What was the power limit for restricted amateur radio licenses in 1922?
- 1/2 kilowatt (500 watts)
- 1 kilowatt (1000 watts)
- 2 kilowatts (2000 watts)
- 5 kilowatts (5000 watts)
Correct Answer: 1/2 kilowatt (500 watts)
Correct Answer Explanation: In 1922, restricted amateur radio licenses in the United States limited power to 1/2 kilowatt (500 watts), reflecting the government’s concern about potential interference from amateur stations and the need to allocate radio spectrum efficiently.
What was the power limit for general amateur radio licenses in 1922?
- 1/2 kilowatt (500 watts)
- 1 kilowatt (1000 watts)
- 2 kilowatts (2000 watts)
- 5 kilowatts (5000 watts)
Correct Answer: 1 kilowatt (1000 watts)
Correct Answer Explanation: General amateur radio licenses allowed for a higher power output of 1 kilowatt (1000 watts), reflecting a greater level of experience and expertise among these operators and the need for more powerful transmitters to reach longer distances.
What was the maximum wave length allowed for amateur radio operators in 1922?
- 200 meters
- 375 meters
- 600 meters
- 1000 meters
Correct Answer: 200 meters
Correct Answer Explanation: Amateur radio licenses in 1922 limited wave lengths to 200 meters, with special licenses allowing for 375 meters, reflecting the government’s allocation of radio spectrum and the need to minimize interference between different types of radio communication.
What was the location of the Westinghouse Company’s station KDKA?
- New York City
- Chicago
- Pittsburgh
- San Francisco
Correct Answer: Pittsburgh
Correct Answer Explanation: The Westinghouse Company’s station KDKA, one of the pioneers of radio broadcasting, was located in Pittsburgh, Pennsylvania, and became famous for broadcasting music, talks, and news programs to a wide audience, demonstrating the transformative potential of radio technology.
What was the range of an amateur aerial for receiving radio signals in 1922?
- 10-25 miles
- 100-200 miles
- 500-1000 miles
- 1000 miles or more
Correct Answer: 1000 miles or more
Correct Answer Explanation: The book states that an amateur aerial, properly designed and constructed, could be used to receive radio signals from distances up to 1000 miles or more, showcasing the remarkable reach of radio communication technology.
What was the range of a simple crystal detector receiving set?
- 10-25 miles
- 100-200 miles
- 500-1000 miles
- 1000 miles or more
Correct Answer: 10-25 miles
Correct Answer Explanation: Simple crystal detector receiving sets, while affordable and easy to construct, had a limited range, typically receiving telegraph or telephone messages from distances of 10-25 miles.
What was the range of a 1/4 kilowatt transmitting set using a quenched spark gap?
- 100-200 miles
- 200 percent greater than a spark coil set
- 500-1000 miles
- 1000 miles or more
Correct Answer: 200 percent greater than a spark coil set
Correct Answer Explanation: In 1922, a 1/4 kilowatt transformer set using a quenched spark gap provided significantly greater range than a spark coil set, approximately 200 percent greater, showcasing the advantages of more advanced technologies for transmitting radio signals over longer distances.
What was the range of a 5-watt oscillator tube?
- 10-25 miles
- 50-100 miles
- 100-200 miles
- 500-1000 miles
Correct Answer: 50-100 miles
Correct Answer Explanation: A 5-watt oscillator tube, powered by a direct current of 350 volts, was capable of transmitting speech and music up to 25 miles, demonstrating the efficiency and power of vacuum tubes in transmitting radio signals.
What was the range of a 50-watt oscillator tube?
- 10-25 miles
- 50-100 miles
- 100-200 miles
- 500-1000 miles
Correct Answer: 100-200 miles
Correct Answer Explanation: A single 50-watt oscillator tube could transmit up to 100 miles, while two in parallel could transmit 100-200 miles, demonstrating the significant increase in range that could be achieved by using more powerful vacuum tubes.
What was the standard resistance of a telephone induction coil in 1922?
- 100-200 ohms
- 500-750 ohms
- 1000-1500 ohms
- 2000-3000 ohms
Correct Answer: 500-750 ohms
Correct Answer Explanation: Telephone induction coils, used to modulate radio signals with audio frequencies, had a standard resistance of 500-750 ohms, ensuring compatibility with various telephone systems and radio transmitters.
What was the output capability of the smallest magnetic modulator?
- 1/2 to 1-1/2 amperes
- 2-4 amperes
- 5-10 amperes
- 10-20 amperes
Correct Answer: 1/2 to 1-1/2 amperes
Correct Answer Explanation: Magnetic modulators, used to modulate radio signals with audio frequencies, came in various sizes, with the smallest capable of delivering 1/2 to 1-1/2 amperes output, reflecting the range of power needed for different radio applications.
What was the plate voltage required for the smallest rectifier tube?
- 100-200 volts
- 350-500 volts
- 550-750 volts
- 1000-1500 volts
Correct Answer: 550-750 volts
Correct Answer Explanation: Rectifier tubes, used to convert alternating current to direct current for powering vacuum tubes, required significant plate voltage to operate. The smallest rectifier tube needed 550 volts plate potential, highlighting the high voltage requirements of vacuum tube technology.
What was the output capability of a 160 milliampere filter reactor?
- 1-4 5-watt oscillator tubes
- 5-10 5-watt oscillator tubes
- 10-20 5-watt oscillator tubes
- 20-40 5-watt oscillator tubes
Correct Answer: 1-4 5-watt oscillator tubes
Correct Answer Explanation: Filter reactors, used to smooth out the direct current output of rectifier tubes, were designed to provide sufficient current for powering multiple vacuum tubes. A 160 milliampere filter reactor could supply current for 1-4 5-watt oscillator tubes, demonstrating the role of these components in supporting the operation of vacuum tube amplifiers.
What is the unit of electric current?
- Volt
- Ampere
- Ohm
- Watt
Correct Answer: Ampere
Correct Answer Explanation: The ampere is the unit of electric current, representing the amount of electric charge flowing through a conductor per unit time.
What is the ability of a device to store an electric charge?
- Inductance
- Capacitance
- Resistance
- Frequency
Correct Answer: Capacitance
Correct Answer Explanation: Capacitance is the ability of a device, such as a capacitor, to store an electric charge. It is measured in farads.
What is the device that converts radio waves into a form that can be heard?
- Detector
- Amplifier
- Oscillator
- Transformer
Correct Answer: Detector
Correct Answer Explanation: A detector is a device that converts radio waves into a form that can be heard. Early detectors used crystal diodes, while later detectors used vacuum tubes.
What is the conductor that carries an electric current into or out of an electrolyte or other medium?
- Resistor
- Capacitor
- Electrode
- Transformer
Correct Answer: Electrode
Correct Answer Explanation: An electrode is a conductor that carries an electric current into or out of an electrolyte or other medium. Electrodes are used in various electronic devices, including batteries, electrolytic capacitors, and vacuum tubes.
What is the number of cycles per second of an alternating current?
- Resistance
- Capacitance
- Frequency
- Inductance
Correct Answer: Frequency
Correct Answer Explanation: The frequency of an alternating current is the number of cycles per second, measured in hertz (Hz).
What is the tendency of a coil of wire to resist changes in the current flowing through it?
- Inductance
- Capacitance
- Resistance
- Frequency
Correct Answer: Inductance
Correct Answer Explanation: Inductance is the tendency of a coil of wire to resist changes in the current flowing through it. It is measured in henries (H).
What are rapid back-and-forth movements of an electric current?
- Oscillations
- Resistance
- Capacitance
- Frequency
Correct Answer: Oscillations
Correct Answer Explanation: Oscillations are rapid back-and-forth movements of an electric current. Oscillations are essential for transmitting radio signals.
What is the opposition to the flow of electric current?
- Inductance
- Capacitance
- Resistance
- Frequency
Correct Answer: Resistance
Correct Answer Explanation: Resistance is the opposition to the flow of electric current. It is measured in ohms (Ω).
What is the device that changes the voltage of an alternating current?
- Detector
- Amplifier
- Oscillator
- Transformer
Correct Answer: Transformer
Correct Answer Explanation: A transformer is a device that changes the voltage of an alternating current. Transformers are used in various applications, including power supplies, radio transmitters, and electrical distribution systems.
What is the device containing a filament, a grid, and a plate, used in various radio applications?
- Resistor
- Capacitor
- Electrode
- Vacuum Tube
Correct Answer: Vacuum Tube
Correct Answer Explanation: A vacuum tube is a device that contains a filament, a grid, and a plate, used in various radio applications, such as amplification, detection, and oscillation.
What is the distance between two successive crests of a wave?
- Frequency
- Resistance
- Wave Length
- Amplitude
Correct Answer: Wave Length
Correct Answer Explanation: The wave length of a wave is the distance between two successive crests or troughs. It is an important parameter in radio communication, as it determines the frequency of the wave.