Did you know that the largest known magnet in the 1800s could lift 40 times its own weight? What was the name of the individual who owned this impressive magnet?
- M. Obelliane
- Sir Isaac Newton
- Dr. Joule
- Professor Dolbear
Correct Answer: M. Obelliane
Correct Answer Explanation: The book mentions that the largest known magnet, belonging to M. Obelliane, could lift an astounding 40 times its own weight. This serves as a testament to the strength of magnets even in those times, laying the foundation for the use of magnetism in the telephone.
Before the invention of the telephone, scientists understood the principles of magnetism, electricity, and sound. Professor Dolbear explains that sound is a form of energy that travels through the air as waves. What is the speed of sound in air at freezing point?
- 1,093 feet per second
- 1,125 feet per second
- 750 feet per second
- 440 feet per second
Correct Answer: 1,093 feet per second
Correct Answer Explanation: Sound travels at a speed of 1,093 feet per second in air at freezing point. This is just one of the many facts about sound explained in “The Telephone,” highlighting the intricate relationship between sound and the science behind the telephone.
What is a magneto-electric machine, as described by Professor Dolbear?
- A machine that generates electricity through friction.
- A machine that generates electricity through chemical action.
- A machine that generates electricity through the motion of coils of wire in front of permanent magnets.
- A machine that generates electricity through the interaction of two coils, one of which is connected to a battery.
Correct Answer: A machine that generates electricity through the motion of coils of wire in front of permanent magnets.
Correct Answer Explanation: Professor Dolbear describes magneto-electric machines as devices that generate electricity by moving coils of wire in the presence of permanent magnets. This process, known as electromagnetic induction, is a core principle that underpins the operation of the telephone.
The book describes how electricity can be generated through various methods. Which of these was NOT mentioned by Dolbear?
- Friction
- Chemical Action
- Thermo-electricity
- Secondary Currents
Correct Answer: Secondary Currents
Correct Answer Explanation: While Dolbear discusses the generation of electricity through friction, chemical action, and thermo-electricity, he doesn’t delve into “secondary currents” in the context of electricity generation. This term is more related to induced currents in coils within an electrical circuit.
Professor Dolbear discusses how sound is created and travels through the air as waves. What determines the pitch of a sound?
- The amplitude of the sound wave.
- The frequency of the sound wave.
- The timbre of the sound wave.
- The resonance of the sound wave.
Correct Answer: The frequency of the sound wave.
Correct Answer Explanation: The pitch of a sound is determined by the frequency of the sound wave. Higher frequencies correspond to higher pitches, while lower frequencies correspond to lower pitches. Understanding this principle is essential to grasping the mechanics of sound transmission in a telephone.
Professor Dolbear discusses the science of sound, including the concept of “timbre.” What contributes to the unique quality of a sound, known as timbre?
- The amplitude of the sound wave.
- The frequency of the sound wave.
- The presence of overtones or harmonics.
- The resonance of the sound wave.
Correct Answer: The presence of overtones or harmonics.
Correct Answer Explanation: Timbre is the unique quality of a sound that distinguishes it from others, even if they have the same pitch and loudness. This distinct quality is determined by the presence of overtones or harmonics, which are additional frequencies that accompany the fundamental tone.
The book explains that sound can be amplified through “resonance.” What is the best example of resonance, as discussed by Professor Dolbear?
- The use of a megaphone to amplify sound.
- The amplification of sound when a vibrating object is placed on a larger, resonant surface.
- The use of a microphone to convert sound into electrical signals.
- The use of a speaker to convert electrical signals into sound.
Correct Answer: The amplification of sound when a vibrating object is placed on a larger, resonant surface.
Correct Answer Explanation: Professor Dolbear explains resonance as the amplification of sound when a vibrating object is placed on a larger, resonant surface. This concept is illustrated through examples like the soundboard of a piano or the resonating chamber of an organ pipe.
Professor Dolbear, like Alexander Graham Bell, was a key figure in the invention of the telephone. Professor Dolbear made a significant contribution by focusing on the science behind the telephone, rather than the mechanics of it. How did Dolbear’s focus on science benefit the field of telephony?
- It allowed him to focus on the development of the technology.
- It helped him to understand the limitations of the existing technology.
- It enabled him to create a more robust and reliable telephone.
- It allowed him to patent his invention and claim ownership of it.
Correct Answer: It enabled him to create a more robust and reliable telephone.
Correct Answer Explanation: Professor Dolbear’s focus on the science behind the telephone allowed him to understand the fundamental principles of electricity, magnetism, and sound, leading to the development of a more robust and reliable telephone. His scientific approach made him less focused on building the physical model of the telephone and more focused on making it work better.
Professor Dolbear’s invention of the speaking-telephone is one of the book’s key topics. What made Dolbear’s telephone different from other inventions?
- It used a vibrating steel plate in front of a powerful magnet to generate electrical pulsations.
- It used a vibrating membrane to interrupt an electric current.
- It used an induction coil and a rotating drum to create musical tones.
- It used a vibrating iron armature to induce electrical pulses in a circuit.
Correct Answer: It used a vibrating steel plate in front of a powerful magnet to generate electrical pulsations.
Correct Answer Explanation: Professor Dolbear’s telephone was unique in that it used a thin steel plate vibrating in front of a powerful magnet to generate electrical pulsations. This process allowed for the transmission of speech, making it a significant breakthrough in the development of the telephone.
What was the name of the device that Dr. Joule invented that could support over 3,500 times its own weight?
- An induction coil
- A magneto-electric machine
- An electromagnet
- A battery
Correct Answer: An electromagnet
Correct Answer Explanation: Dr. Joule’s electromagnet, as mentioned in the book, had the remarkable capability of supporting over 3,500 times its own weight. This demonstrates the power of electromagnets and their potential for various applications, including the telephone.
What type of electricity is associated with lightning?
- Static electricity
- Dynamic electricity
- Magneto-electricity
- Thermo-electricity
Correct Answer: Static electricity
Correct Answer Explanation: Lightning is a striking example of static electricity. It occurs when a buildup of static charge in the atmosphere suddenly discharges, creating a powerful flash of light and sound.
Professor Dolbear explores the concept of “overtones” in the book. What are overtones in relation to sound?
- The lowest and usually strongest tone in a musical sound.
- Harmonics or upper partial tones that accompany the fundamental tone in a musical sound.
- The unique quality of a sound, distinct from its pitch.
- The tendency of objects to vibrate at their resonant frequencies when exposed to sound waves of that frequency.
Correct Answer: Harmonics or upper partial tones that accompany the fundamental tone in a musical sound.
Correct Answer Explanation: Overtones, also known as harmonics, are additional frequencies that accompany the fundamental tone of a sound. They contribute to the timbre, or unique quality, of different instruments and voices.
The book describes the “Helmholtz’ Electric Interrupter.” What was the purpose of this device?
- To create a sound of a specific pitch by breaking a circuit in sync with the vibrations of a tuning fork.
- To amplify sound vibrations using a resonant surface.
- To convert sound waves into electrical signals.
- To convert electrical signals into sound waves.
Correct Answer: To create a sound of a specific pitch by breaking a circuit in sync with the vibrations of a tuning fork.
Correct Answer Explanation: Helmholtz’ Electric Interrupter was a device that used the vibrations of a tuning fork to repeatedly break and restore an electric circuit. This process generated a sound with a specific pitch, demonstrating the connection between electrical signals and sound production.
Professor Dolbear explains that a “fundamental tone” is present in musical sounds. What is the fundamental tone?
- The lowest and usually strongest tone in a musical sound.
- The highest tone in a musical sound.
- The tone that is most pleasing to the human ear.
- The tone that is most easily produced by an instrument.
Correct Answer: The lowest and usually strongest tone in a musical sound.
Correct Answer Explanation: The fundamental tone, also known as the first harmonic, is the lowest and typically strongest tone in a musical sound. It forms the basis for the sound and is accompanied by overtones, which contribute to the overall timbre.
Which of the following is NOT mentioned as a method for generating electricity in the book?
- Friction
- Chemical Action
- Magneto-electricity
- Photoelectricity
Correct Answer: Photoelectricity
Correct Answer Explanation: While the book covers friction, chemical action, and magneto-electricity as methods for generating electricity, it doesn’t mention photoelectricity. Photoelectricity refers to the emission of electrons from a material when light shines on it, a principle that wasn’t fully explored until the early 20th century.
What is the term for the process of generating electricity in a coil of wire by changing the magnetic field near it?
- Polarization
- Induction
- Resonance
- Sympathetic Vibrations
Correct Answer: Induction
Correct Answer Explanation: Induction is the process of generating electricity in a coil of wire by changing the magnetic field near it. This principle is crucial for the operation of the telephone and many other electrical devices.
What is the standard pitch, or frequency, of the note “A” in a musical scale?
- 440 vibrations per second
- 1,093 vibrations per second
- 1,125 vibrations per second
- 23 vibrations per second
Correct Answer: 440 vibrations per second
Correct Answer Explanation: The standard pitch, or frequency, of the note “A” in a musical scale is 440 vibrations per second. This pitch, known as “concert A,” serves as a reference for tuning instruments and is used widely in music.
Professor Dolbear discusses the “lovers’ telegraph” in his book. What is the lovers’ telegraph?
- A simple device using a taut string to transmit sound between two tin cans.
- A system of flags and signals used to communicate over long distances.
- A method of sending messages using carrier pigeons.
- A type of semaphore system used in the military.
Correct Answer: A simple device using a taut string to transmit sound between two tin cans.
Correct Answer Explanation: The “lovers’ telegraph” is a simple device that uses a taut string to transmit sound between two tin cans. It demonstrates the basic principle of sound transmission through a medium, albeit in a rudimentary form.
What is the term used to describe the buildup of unwanted chemical products on the electrodes of a battery cell?
- Polarization
- Induction
- Resonance
- Sympathetic Vibrations
Correct Answer: Polarization
Correct Answer Explanation: Polarization refers to the buildup of unwanted chemical products on the electrodes of a battery cell, reducing its efficiency. This phenomenon is relevant to the understanding of electrical currents and their effects on battery performance.
In his book, Professor Dolbear explains the concept of “sympathetic vibrations.” What is the best description of this phenomenon?
- The tendency of objects to vibrate at their resonant frequencies when exposed to sound waves of that frequency.
- The amplification of sound waves when a vibrating object is placed on a surface that can vibrate at the same frequency.
- The unique quality of a sound, distinct from its pitch.
- The process of generating electricity in a coil of wire by changing the magnetic field near it.
Correct Answer: The tendency of objects to vibrate at their resonant frequencies when exposed to sound waves of that frequency.
Correct Answer Explanation: Sympathetic vibrations occur when an object is exposed to sound waves at its resonant frequency, causing it to vibrate along with the sound. This phenomenon is evident in various musical instruments and contributes to the amplification of sound.
The book describes how the “organ pipes” produce sound. What is the primary mechanism by which an organ pipe produces sound?
- The vibration of a column of air inside the pipe.
- The vibration of a stretched string inside the pipe.
- The vibration of a reed inside the pipe.
- The vibration of a diaphragm inside the pipe.
Correct Answer: The vibration of a column of air inside the pipe.
Correct Answer Explanation: Organ pipes produce sound through the vibration of a column of air inside the pipe. The shape and size of the pipe influence the length of the air column and, consequently, the pitch of the sound produced.
The book discusses the “human voice” in detail. What makes the human voice so unique and challenging to understand scientifically?
- It is rich in overtones and highly individual, making it impossible to tabulate the components of its timbre.
- It is produced by a complex system of muscles and vocal cords.
- It can produce a wide range of frequencies and volumes.
- It is highly adaptable and can be used to communicate a wide range of emotions.
Correct Answer: It is rich in overtones and highly individual, making it impossible to tabulate the components of its timbre.
Correct Answer Explanation: The human voice is rich in overtones and highly individual, making it impossible to tabulate the components of its timbre. This makes it a complex phenomenon to understand scientifically, as each person’s voice has a unique blend of harmonics and overtones.
Professor Dolbear explains the concept of “intermittent current.” What is an intermittent current?
- A current that is repeatedly broken and restored.
- A current that flows in only one direction.
- A current that is constant and unchanging.
- A current that is induced by a changing magnetic field.
Correct Answer: A current that is repeatedly broken and restored.
Correct Answer Explanation: An intermittent current is one that is repeatedly broken and restored. This type of current is often used in telephony and other applications where the signal needs to be modulated or interrupted to convey information.
What was the name of the inventor who used a vibrating membrane to interrupt an electric current, producing a sound with the same pitch as the source but lacking the complexity of speech?
- Reiss
- Gray
- Bell
- Dolbear
Correct Answer: Reiss
Correct Answer Explanation: Reiss’s telephone used a vibrating membrane to interrupt an electric current, generating a sound with the same pitch as the source but lacking the complexity of speech. This invention was a significant step towards the development of a speaking telephone but lacked the ability to transmit the full range of human speech.
Professor Dolbear describes an experiment using a “tuning fork and bottle.” What does this experiment demonstrate?
- The relationship between sound frequency and the length of a resonant air column.
- The amplification of sound by a resonant surface.
- The transmission of sound through a medium.
- The production of sound by a vibrating object.
Correct Answer: The relationship between sound frequency and the length of a resonant air column.
Correct Answer Explanation: The experiment with a tuning fork and bottle demonstrates the relationship between sound frequency and the length of a resonant air column. When a tuning fork is placed near a bottle filled to a specific depth with water, the air column in the bottle will resonate at the same frequency as the tuning fork, amplifying the sound.
What is the name of the inventor who employed a vibrating iron armature to induce electrical pulses in a circuit, enabling the transmission of speech?
- Reiss
- Gray
- Bell
- Dolbear
Correct Answer: Bell
Correct Answer Explanation: Alexander Graham Bell’s telephone used a vibrating iron armature to induce electrical pulses in a circuit, enabling the transmission of speech. This innovation was a crucial step in the development of a practical speaking telephone.
The book describes how “magnetic cars” were used in ancient China. What were these magnetic cars used for?
- To navigate vast steppes of Tartary.
- To transport goods over long distances.
- To demonstrate the principles of magnetism.
- To create a mystical illusion of levitation.
Correct Answer: To navigate vast steppes of Tartary.
Correct Answer Explanation: The book mentions that magnetic cars were used in ancient China to navigate vast steppes of Tartary. These cars were essentially compasses, utilizing the earth’s magnetic field for direction-finding.
What is the term for the highest frequency of sound that a human can typically hear?
- Lower limit
- Upper limit
- Resonant frequency
- Fundamental frequency
Correct Answer: Upper limit
Correct Answer Explanation: The upper limit refers to the highest frequency of sound that a human can typically hear. This limit varies significantly between individuals and typically decreases with age.
What is the name of the instrument that uses a thin rubber membrane to visualize sound vibrations through the reflection of light?
- Opeidoscope
- Helmholtz’ Electric Interrupter
- Reiss’ Telephone
- Gray’s Musical Telephone
Correct Answer: Opeidoscope
Correct Answer Explanation: The opeidoscope is an instrument that uses a thin rubber membrane to visualize sound vibrations through the reflection of light. The membrane vibrates in response to sound waves, causing changes in the reflection of light and making the sound waves visible.
What is the name of the device that enabled the transmission of musical sounds by using electromagnets to vibrate reeds tuned to specific frequencies?
- Reiss’ Telephone
- Gray’s Musical Telephone
- Bell’s Telephone
- Dolbear’s Telephone
Correct Answer: Gray’s Musical Telephone
Correct Answer Explanation: Gray’s Musical Telephone used electromagnets to vibrate reeds tuned to specific frequencies, enabling the transmission of musical sounds. This invention demonstrated the potential of the telephone for transmitting more than just speech.
In the book, Professor Dolbear provides specific instructions for building a speaking-telephone. What material was used for the plate that vibrated in front of the magnet in Professor Dolbear’s telephone?
- Iron
- Steel
- Copper
- Aluminum
Correct Answer: Steel
Correct Answer Explanation: Professor Dolbear used a thin steel plate that vibrated in front of a powerful magnet to generate electrical pulsations in his telephone.
What was the approximate length of the spark produced by De La Rue’s battery, which consisted of 8,040 cells?
- 0.345 inches
- 21 inches
- 42 inches
- 50 miles
Correct Answer: 0.345 inches
Correct Answer Explanation: De La Rue’s battery, consisting of 8,040 cells, produced a spark approximately 0.345 inches long. This was a significant achievement in the field of electricity at the time and demonstrated the power of large battery systems.
What is the term for the force generated by magnetic materials, affecting other magnetic materials and electric currents?
- Electricity
- Magnetism
- Electromagnetism
- Polarization
Correct Answer: Magnetism
Correct Answer Explanation: Magnetism is the force generated by magnetic materials, affecting other magnetic materials and electric currents. This force is fundamental to the operation of the telephone and many other electrical devices.
The book describes how the “violin” produces sound. What makes the violin’s sound so complex and unique?
- The numerous overtones it can produce.
- The use of a bow to set the strings in motion.
- The resonance of the body of the instrument.
- The interaction between the strings and the bridge.
Correct Answer: The numerous overtones it can produce.
Correct Answer Explanation: The violin’s sound is complex and unique due to the numerous overtones it can produce. These overtones contribute to the rich and varied timbre of the instrument.
What was the approximate length of the spark produced by the largest known induction coil at the time, built by Spottiswood?
- 21 inches
- 42 inches
- 50 miles
- 280 miles
Correct Answer: 42 inches
Correct Answer Explanation: The largest known induction coil at the time, built by Spottiswood, used 280 miles of secondary wire and generated a spark 42 inches long. This was a remarkable feat of electrical engineering and demonstrated the potential of induction coils for producing high-voltage electricity.
What is the term used to describe the unique quality of a sound, distinct from its pitch, determined by the presence of overtones?
- Amplitude
- Frequency
- Resonance
- Timbre
Correct Answer: Timbre
Correct Answer Explanation: Timbre refers to the unique quality of a sound, distinct from its pitch and loudness, which is determined by the presence of overtones. Different instruments and voices have distinct timbres, making them sound unique even when playing the same note at the same volume.
What was the name of the scientist who performed experiments with magnets and discovered that a 3-grain magnet could lift 750 grains, 250 times its weight?
- Professor Dolbear
- Sir Isaac Newton
- Dr. Joule
- Alexander Graham Bell
Correct Answer: Sir Isaac Newton
Correct Answer Explanation: Sir Isaac Newton conducted experiments with magnets and discovered that a 3-grain magnet could lift 750 grains, 250 times its weight. This discovery highlighted the power of magnets and their ability to exert forces far greater than their own weight.
The book explains how the “piano sounding board” contributes to the instrument’s sound. What is the primary function of the sounding board in a piano?
- To amplify the vibrations of the piano strings.
- To damp the vibrations of the piano strings.
- To tune the piano strings to specific pitches.
- To provide a surface for the hammers to strike.
Correct Answer: To amplify the vibrations of the piano strings.
Correct Answer Explanation: The sounding board in a piano is a large, thin board that amplifies the vibrations of the piano strings. This amplification contributes to the overall volume and richness of the piano’s sound.
What is the term for the interaction between electricity and magnetism, where electric currents create magnetic fields and magnetic fields can induce electric currents?
- Electricity
- Magnetism
- Electromagnetism
- Polarization
Correct Answer: Electromagnetism
Correct Answer Explanation: Electromagnetism is the interaction between electricity and magnetism, where electric currents create magnetic fields and magnetic fields can induce electric currents. This fundamental principle underlies the operation of the telephone, electric motors, and many other technologies.
The book describes the “comb and paper” experiment. What does this experiment demonstrate?
- How membranes respond to vibrations.
- The transmission of sound through a medium.
- The amplification of sound by a resonant surface.
- The production of sound by a vibrating object.
Correct Answer: How membranes respond to vibrations.
Correct Answer Explanation: The “comb and paper” experiment demonstrates how membranes respond to vibrations. When a strip of paper is placed in front of a vibrating comb, it will vibrate along with the comb, producing a sound. This illustrates the principle of how membranes can be used to transmit and amplify sound waves.