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Q1. SONAR helps in finding
SONAR (Sound Navigation And Ranging) is mainly used to measure the depth of the sea and locate underwater objects like submarines, icebergs, and sunken ships. It works by sending ultrasonic waves into water and measuring the time taken for the echo to return. It is not used to measure mountain height, water temperature, or wind speed.
Q2. Another name for eardrum is
The eardrum is also called the tympanic membrane. It is a thin, stretched membrane at the end of the auditory canal that vibrates when sound waves strike it. The stirrup, oval window, and cochlea are other parts of the ear, but the eardrum specifically is the tympanic membrane.
Q3. SONAR is mainly used to detect
SONAR is mainly used to detect underwater objects such as submarines, icebergs, sunken ships, and the sea floor. It uses ultrasonic waves to locate objects beneath the water surface. It is not used for detecting underground minerals, airborne objects, or space debris.
Q4. Hearing involves conversion of sound into
Hearing involves the conversion of sound waves into electrical signals. The ear receives sound vibrations, and the cochlea converts these mechanical vibrations into electrical impulses that are sent to the brain for interpretation. This is the fundamental process of hearing.
Q5. The detector converts ultrasonic waves into
In SONAR and other ultrasonic systems, the detector (receiver) converts the reflected ultrasonic waves into electrical signals. These signals are then processed and displayed. The conversion is from mechanical waves (sound) to electrical signals, not light, heat, or magnetic signals.
Q6. Reflections help bats to detect
Bats use echolocation by emitting ultrasonic waves and detecting their reflections. The reflected sound waves help them to detect obstacles and locate prey, even in complete darkness. They do not use reflections to detect temperature, weather, or wind direction.
Q7. Ultrasonic waves have frequencies
Ultrasonic waves have frequencies above the audible range of human hearing, i.e., greater than 20,000 Hz (20 kHz). They are not the same as radio waves, are not in the audible range, and are not below the audible range (which would be infrasound).
Q8. SONAR works using
SONAR works using ultrasonic waves (high-frequency sound waves). It sends ultrasonic pulses into water and detects the echoes to locate objects. Infrared waves, light waves, and radio waves are not used in SONAR because they do not travel well through water.
Q9. The nature of reflected sound tells the bat
The nature of reflected sound (echo) tells the bat the location (distance and direction) and the nature (size, texture, movement) of the object. It does not tell wind speed, time of night, or just distance. The reflected waves provide detailed information about the environment.
Q10. SONAR is installed in
SONAR is installed in boats, ships, and submarines to detect underwater objects and measure the depth of the sea. It is not used in satellites (which use radio waves) or aeroplanes (which use radar). Submarines also use SONAR, but the general answer is boats or ships.
Q11. The pinna helps in
The pinna (the outer visible part of the ear) helps in collecting sound waves from the surroundings and directing them into the auditory canal. It does not create vibrations (the eardrum does), amplify signals (the middle ear bones do), or specifically help with loud sounds.
Q12. Audible frequencies are detected by
Audible frequencies (20 Hz to 20,000 Hz) are detected by the ear. The nose detects smell, skin detects touch and temperature, and eyes detect light. The ear is the organ responsible for hearing.
Q13. The human ear is a device that converts
The human ear converts pressure variations (sound waves) into electrical signals that the brain can interpret. The sound waves cause the eardrum to vibrate, and these vibrations are ultimately converted into electrical signals by the cochlea. It does not convert light, electricity, or heat into sound.
Q14. Bats navigate in the dark using
Bats navigate in the dark using ultrasonic waves (echolocation). They emit high-frequency sound waves and listen to the echoes to create a mental map of their surroundings. They do not use radio, infrared, or light waves for navigation.
Q15. Electrical signals from cochlea are sent to
Electrical signals from the cochlea are sent to the brain via the auditory nerve. The brain interprets these signals as sound. The lungs, heart, and spinal cord are not involved in sound interpretation.
Q16. Electrical signals from the ear travel to the brain via
Electrical signals from the ear travel to the brain via the auditory nerve. The motor nerve controls muscles, the optic nerve carries visual signals, and the spinal cord is not the direct pathway for sound. The auditory nerve is specifically for hearing.
Q17. The brain interprets electrical signals as
The brain interprets electrical signals from the auditory nerve as sound. This is the final step in the hearing process. Light, motion, and heat are interpreted by different parts of the brain (vision, movement, and temperature).
Q18. Porpoises use ultrasound for
Porpoises (and dolphins) use ultrasound for navigation and locating food (echolocation). They also use it for communication, but the primary use is for navigation and hunting. They do not use it for sleeping or making nests.
Q19. Vibrations are amplified in the
Vibrations are amplified in the middle ear by the three tiny bones (hammer, anvil, and stirrup). These bones act as a lever system to increase the force of vibrations before they reach the inner ear. The outer ear collects sound, and the inner ear converts vibrations to electrical signals.
Q20. Distance in SONAR is calculated using
Distance in SONAR is calculated using the formula: distance = speed × time / 2. The time taken for the ultrasonic wave to travel to the object and back is measured, and the speed of sound in water is used to calculate the distance. Loudness, amplitude, and frequency do not directly give distance.
Q21. The method used by SONAR to calculate distance is called
The method used by SONAR to calculate distance is called echo-ranging. It involves sending a pulse of sound and measuring the time it takes for the echo to return. The distance is then calculated from the time delay and the speed of sound. Refraction, diffraction, and interference are different wave phenomena.
Q22. The reflected ultrasonic waves are sensed by
In SONAR, the reflected ultrasonic waves are sensed by the detector (or receiver). The detector captures the returning echoes and converts them into electrical signals for processing. The transmitter sends out the waves, and the receiver/detector captures the reflected waves.
Q23. SONAR can detect
SONAR can detect underwater objects like icebergs, submarines, sunken ships, and the sea floor. It cannot detect volcanoes (which are detected by other methods), rainfall, or lightning. Icebergs are large masses of ice floating in water, and SONAR can locate them.
Q24. The thin membrane at the end of auditory canal is
The thin membrane at the end of the auditory canal is the eardrum (tympanic membrane). It vibrates when sound waves strike it, initiating the hearing process. The cochlea is the spiral-shaped organ in the inner ear, the auditory nerve transmits signals, and the pinna is the outer ear.
Q25. The ear converts sound waves into
The ear converts sound waves (mechanical energy) into electrical signals (neural impulses) that the brain can interpret. This conversion happens in the cochlea. It does not convert sound into heat, chemical, or mechanical energy directly.
Q26. The formula used in SONAR is
In SONAR, the formula used is 2d = vt, where d is the distance to the object, v is the speed of sound in the medium, and t is the time taken for the sound to travel to the object and back. This accounts for the round trip. The other formulas are either incomplete or incorrect.
Q27. SONAR can locate
SONAR can locate sunken ships and other underwater objects. It is not used to locate satellites (which are in space), meteors, or airplanes (which are detected by radar). SONAR is specifically for underwater detection.
Q28. In SONAR, ‘v’ represents
In SONAR, ‘v’ represents the speed of sound in water (or the medium). This value is used in the formula 2d = vt to calculate the distance to an underwater object. It is not volume, vibration rate, or the velocity of the ship.
Q29. In SONAR, ‘t’ represents
In SONAR, ‘t’ represents the time interval between sending the ultrasonic pulse and receiving the echo. This time is used in the formula 2d = vt to calculate the distance. It is not thickness, temperature, or tension.
Q30. The three bones in the middle ear are
The three bones in the middle ear are the hammer (malleus), anvil (incus), and stirrup (stapes). These bones amplify the vibrations from the eardrum and transmit them to the inner ear. The other options contain incorrect structures.
Q31. The middle ear transmits vibrations to
The middle ear transmits amplified vibrations from the eardrum to the inner ear (specifically, the oval window of the cochlea). The outer ear collects sound, the auditory canal directs sound, and the brain interprets signals. The middle ear is the bridge between the outer and inner ear.
Q32. SONAR consists of
SONAR consists of a transmitter (which sends out ultrasonic waves) and a detector (which receives the reflected echoes). The transmitter and detector are essential components for echo-ranging. Antenna and receiver are used for radio waves, not SONAR.
Q33. Bats emit high-pitched
Bats emit high-pitched ultrasonic squeaks for echolocation. These are beyond the range of human hearing. They do not emit audible sounds (though some are audible), light flashes, or radio signals. Ultrasonic squeaks are their primary means of navigation.
Q34. Ultrasonic waves are reflected back after striking
Ultrasonic waves are reflected back after striking underwater objects (submarines, icebergs, fish, sea floor). The reflected echoes return to the detector. The ship, air surface, and detector are not the primary reflecting objects; the waves reflect off objects in the water.
Q35. Sound collected by pinna passes through
Sound collected by the pinna passes through the auditory canal (ear canal) to reach the eardrum. The middle ear, cochlea, and eardrum are later in the hearing process. The pinna directs sound into the auditory canal first.
Q36. SONAR works on the principle of
SONAR works on the principle of reflection of sound (echo). It sends ultrasonic waves and detects the reflected echoes. Refraction, interference, and diffraction are other wave phenomena, but SONAR relies on reflection to determine distance and location.
Q37. Rarefaction causes the eardrum to
Rarefaction is a region of low pressure. When a rarefaction reaches the eardrum, it causes the eardrum to move outward. Compression (high pressure) causes it to move inward. The eardrum vibrates back and forth in response to alternating compressions and rarefactions.
Q38. The speed of ultrasound in seawater is approximately
The speed of ultrasound in seawater is approximately 1531 m/s (depending on temperature, salinity, and pressure). 343 m/s is the speed of sound in air, 1200 m/s is too low, and 3000 m/s is too high. 1531 m/s is the standard value for seawater.
Q39. The eardrum vibrates due to
The eardrum vibrates due to pressure variations in the sound waves. Sound waves consist of alternating compressions (high pressure) and rarefactions (low pressure), which cause the eardrum to move back and forth. Heat, electricity, and light do not cause the eardrum to vibrate.
Q40. Ultrasonic waves travel through
Ultrasonic waves travel through water (and other media like solids and tissues). They cannot travel through a vacuum. While they can travel through air and glass, the most relevant medium for SONAR applications is water. The question likely refers to the typical medium for ultrasound in SONAR.
Q41. The transmitter in SONAR produces
The transmitter in SONAR produces ultrasonic waves (high-frequency sound waves) that are sent into the water. It does not produce light waves, audible sound (in the human range), or just electrical signals. The transmitter generates the ultrasonic pulses.
Q42. SONAR is used to locate
SONAR is used to locate submarines and other underwater objects. It is not used to locate stars (telescopes), birds (vision or radar), or clouds (weather radar). SONAR is specifically for underwater detection.
Q43. The auditory canal directs sound towards
The auditory canal directs sound waves from the pinna towards the eardrum (tympanic membrane). The cochlea, brain, and auditory nerve are involved later in the hearing process. The eardrum is the first structure to be struck by the sound waves.
Q44. Compression increases pressure on the eardrum causing it to
A compression (region of high pressure) increases the pressure on the eardrum, causing it to move inward. A rarefaction (low pressure) causes it to move outward. This alternating inward and outward movement is what constitutes the vibration of the eardrum.
Q45. The total distance travelled by ultrasound in SONAR is
In SONAR, the total distance travelled by the ultrasound is 2d, where d is the distance from the source to the object. The sound travels to the object and back, so the total distance is twice the one-way distance. The formula 2d = vt reflects this.
Q46. The outer ear is called
The outer ear is called the pinna (or auricle). It is the visible part of the ear that collects sound waves. The stirrup and anvil are bones in the middle ear, and the cochlea is in the inner ear. The pinna is the correct name for the outer ear.
Q47. Echo-ranging depends on
Echo-ranging depends on the time delay between the emission of a sound pulse and the reception of its echo. The distance to the object is calculated from this time delay and the speed of sound. Intensity, loudness, and pitch are not the primary factors in echo-ranging.
Q48. The inner ear converts vibrations into
The inner ear (specifically the cochlea) converts the mechanical vibrations from the middle ear into electrical signals (nerve impulses). These electrical signals are then sent to the brain via the auditory nerve. It does not convert vibrations into light, sound, or heat.
Q49. The organ responsible for conversion into electrical signals is
The cochlea in the inner ear is responsible for converting mechanical vibrations into electrical signals. The anvil is a middle ear bone, the eardrum vibrates, and the pinna collects sound. The cochlea is the organ that performs the transduction of sound to electrical signals.
Q50. SONAR stands for
SONAR stands for Sound Navigation And Ranging. It is a technique that uses sound propagation (usually ultrasonic) to navigate, communicate, or detect objects underwater. The other options are incorrect expansions.
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