The working system of radar is based on [B] reflection of radio waves. Radar operates by transmitting short pulses of radio waves from a radar antenna. These waves travel through the atmosphere until they encounter an object, such as an aircraft or ship. Upon hitting the object, some of the radio waRead more
The working system of radar is based on [B] reflection of radio waves. Radar operates by transmitting short pulses of radio waves from a radar antenna. These waves travel through the atmosphere until they encounter an object, such as an aircraft or ship. Upon hitting the object, some of the radio waves are reflected back towards the radar antenna.
The radar system then analyzes the time it takes for the radio waves to return (to determine distance), as well as any Doppler shift in frequency (to determine speed and direction of the object). This principle of radio wave reflection forms the basis of radar technology, which is crucial for applications in aviation, maritime navigation, weather forecasting, and military surveillance.
Options [A] (refraction of radio waves), [C] (Doppler effect), and [D] (Raman effect) are not directly related to the fundamental operation of radar systems, making [B] reflection of radio waves the correct answer.
To hear a clear echo, there should be a minimum distance between the reflecting plane and the sound source of [B] 17 meters. This distance allows for a distinct time delay between the emission of sound and the reflection off a surface, making the echo audible to the listener. When the sound travelsRead more
To hear a clear echo, there should be a minimum distance between the reflecting plane and the sound source of [B] 17 meters. This distance allows for a distinct time delay between the emission of sound and the reflection off a surface, making the echo audible to the listener.
When the sound travels to a surface and back within a short distance, the reflected sound arrives too quickly to be perceived as an echo. As the distance increases, the time gap between the original sound and its reflection grows, resulting in a more noticeable echo.
Understanding this minimum distance helps in designing spaces for acoustic effects, such as concert halls and outdoor environments, where echoes can enhance or detract from the quality of sound. Therefore, the correct answer for hearing a clear echo is [B] 17 meters.
The cause of echo is primarily [A] reflection of sound. When sound waves encounter a large and hard surface, such as a building, cliff, or canyon wall, they reflect off the surface and return towards the source. If the distance to the reflecting surface is significant enough, the reflected sound reaRead more
The cause of echo is primarily [A] reflection of sound. When sound waves encounter a large and hard surface, such as a building, cliff, or canyon wall, they reflect off the surface and return towards the source. If the distance to the reflecting surface is significant enough, the reflected sound reaches the listener’s ears distinctly after the original sound, creating an echo. The perception of an echo depends on the time delay between the direct sound and its reflection.
Absorption of sound (option [C]) reduces echo by absorbing sound waves rather than reflecting them. Refraction of sound (option [B]) involves the bending of sound waves due to changes in temperature or density gradients, but it does not cause echoes directly. The speed of sound (option [D]) affects the timing of echo perception but is not the direct cause of echo itself. Therefore, reflection of sound (option [A]) is correctly identified as the cause of echo.
The decibel (dB) unit is primarily used for [C] the intensity of sound. It provides a logarithmic scale to measure the loudness or intensity of sound waves. Decibels allow us to quantify sound levels across a wide range, from the faintest audible sounds to extremely loud noises that can cause hearinRead more
The decibel (dB) unit is primarily used for [C] the intensity of sound. It provides a logarithmic scale to measure the loudness or intensity of sound waves. Decibels allow us to quantify sound levels across a wide range, from the faintest audible sounds to extremely loud noises that can cause hearing damage. This unit is crucial in various fields such as acoustics, engineering, and environmental science for assessing and managing noise levels.
Unlike options [A], [B], and [D], which are associated with different physical quantities (speed of light, intensity of heat, and frequency of radio waves, respectively), the decibel specifically denotes sound intensity. It helps describe how sound energy is perceived by the human ear, providing a standardized way to communicate and regulate sound levels in various contexts, from everyday environments to industrial settings and entertainment venues.
While shouting, a person keeps the palm near the mouth primarily because [A] in that position, the sound energy will point in one direction only. By cupping the hand around the mouth, the person creates a makeshift horn or amplifier that directs the sound waves forward. This action helps to concentrRead more
While shouting, a person keeps the palm near the mouth primarily because [A] in that position, the sound energy will point in one direction only. By cupping the hand around the mouth, the person creates a makeshift horn or amplifier that directs the sound waves forward. This action helps to concentrate and focus the sound energy towards the intended target or direction, increasing the intensity and clarity of the shout. It can be particularly useful in noisy environments or over distances where clear communication is necessary. This technique does not change the completeness or tone of the sound (options [B] and [C]), but rather improves the efficiency of projecting the sound waves in a specific direction. Therefore, option [A] correctly describes why people use this method while shouting.
The working system of radar is based on the following principle
The working system of radar is based on [B] reflection of radio waves. Radar operates by transmitting short pulses of radio waves from a radar antenna. These waves travel through the atmosphere until they encounter an object, such as an aircraft or ship. Upon hitting the object, some of the radio waRead more
The working system of radar is based on [B] reflection of radio waves. Radar operates by transmitting short pulses of radio waves from a radar antenna. These waves travel through the atmosphere until they encounter an object, such as an aircraft or ship. Upon hitting the object, some of the radio waves are reflected back towards the radar antenna.
The radar system then analyzes the time it takes for the radio waves to return (to determine distance), as well as any Doppler shift in frequency (to determine speed and direction of the object). This principle of radio wave reflection forms the basis of radar technology, which is crucial for applications in aviation, maritime navigation, weather forecasting, and military surveillance.
Options [A] (refraction of radio waves), [C] (Doppler effect), and [D] (Raman effect) are not directly related to the fundamental operation of radar systems, making [B] reflection of radio waves the correct answer.
See lessTo hear a clear echo, there should be a minimum distance between the reflecting plane and the sound source
To hear a clear echo, there should be a minimum distance between the reflecting plane and the sound source of [B] 17 meters. This distance allows for a distinct time delay between the emission of sound and the reflection off a surface, making the echo audible to the listener. When the sound travelsRead more
To hear a clear echo, there should be a minimum distance between the reflecting plane and the sound source of [B] 17 meters. This distance allows for a distinct time delay between the emission of sound and the reflection off a surface, making the echo audible to the listener.
When the sound travels to a surface and back within a short distance, the reflected sound arrives too quickly to be perceived as an echo. As the distance increases, the time gap between the original sound and its reflection grows, resulting in a more noticeable echo.
Understanding this minimum distance helps in designing spaces for acoustic effects, such as concert halls and outdoor environments, where echoes can enhance or detract from the quality of sound. Therefore, the correct answer for hearing a clear echo is [B] 17 meters.
See lessThe cause of echo is
The cause of echo is primarily [A] reflection of sound. When sound waves encounter a large and hard surface, such as a building, cliff, or canyon wall, they reflect off the surface and return towards the source. If the distance to the reflecting surface is significant enough, the reflected sound reaRead more
The cause of echo is primarily [A] reflection of sound. When sound waves encounter a large and hard surface, such as a building, cliff, or canyon wall, they reflect off the surface and return towards the source. If the distance to the reflecting surface is significant enough, the reflected sound reaches the listener’s ears distinctly after the original sound, creating an echo. The perception of an echo depends on the time delay between the direct sound and its reflection.
Absorption of sound (option [C]) reduces echo by absorbing sound waves rather than reflecting them. Refraction of sound (option [B]) involves the bending of sound waves due to changes in temperature or density gradients, but it does not cause echoes directly. The speed of sound (option [D]) affects the timing of echo perception but is not the direct cause of echo itself. Therefore, reflection of sound (option [A]) is correctly identified as the cause of echo.
See lessDecibel unit is used for
The decibel (dB) unit is primarily used for [C] the intensity of sound. It provides a logarithmic scale to measure the loudness or intensity of sound waves. Decibels allow us to quantify sound levels across a wide range, from the faintest audible sounds to extremely loud noises that can cause hearinRead more
The decibel (dB) unit is primarily used for [C] the intensity of sound. It provides a logarithmic scale to measure the loudness or intensity of sound waves. Decibels allow us to quantify sound levels across a wide range, from the faintest audible sounds to extremely loud noises that can cause hearing damage. This unit is crucial in various fields such as acoustics, engineering, and environmental science for assessing and managing noise levels.
Unlike options [A], [B], and [D], which are associated with different physical quantities (speed of light, intensity of heat, and frequency of radio waves, respectively), the decibel specifically denotes sound intensity. It helps describe how sound energy is perceived by the human ear, providing a standardized way to communicate and regulate sound levels in various contexts, from everyday environments to industrial settings and entertainment venues.
See lessWhile shouting, a person always keeps the palm near the mouth, because
While shouting, a person keeps the palm near the mouth primarily because [A] in that position, the sound energy will point in one direction only. By cupping the hand around the mouth, the person creates a makeshift horn or amplifier that directs the sound waves forward. This action helps to concentrRead more
While shouting, a person keeps the palm near the mouth primarily because [A] in that position, the sound energy will point in one direction only. By cupping the hand around the mouth, the person creates a makeshift horn or amplifier that directs the sound waves forward. This action helps to concentrate and focus the sound energy towards the intended target or direction, increasing the intensity and clarity of the shout. It can be particularly useful in noisy environments or over distances where clear communication is necessary. This technique does not change the completeness or tone of the sound (options [B] and [C]), but rather improves the efficiency of projecting the sound waves in a specific direction. Therefore, option [A] correctly describes why people use this method while shouting.
See less