HARD
Earn 100

What is SONAR? What is its use? List the characteristics of sound wave.

Important Questions on Sound

EASY
Science>Physics>Sound>Applications of Ultrasound
The acronym ‘SONAR’ stands for
EASY
Science>Physics>Sound>Applications of Ultrasound
Sound travels at a speed of 1450 ms-1through water. A submarine detects objects around it by sending sound waves and detecting echo (reflected sound) heard after 4 s. Then the object must be at a distance of:
EASY
Science>Physics>Sound>Applications of Ultrasound
If the velocity of sound in air is 340 m s-1 and x is the minimum distance between sound source and reflecting surface to get echo from general sound, then :
EASY
Science>Physics>Sound>Applications of Ultrasound

A person clapped his hands near a cliff and heard the echo after 4 s. The distance between the cliff and the person will be :

(Speed of sound is 346 m s-1) 

EASY
Science>Physics>Sound>Applications of Ultrasound
A man who is standing at a distance of 850 m from a sound reflecting surface claps loudly. If the velocity of the sound in air is 340 ms-1 then the time taken by the echo to reach him is
EASY
Science>Physics>Sound>Applications of Ultrasound
What is the minimum distance required to hear an echo in air?
EASY
Science>Physics>Sound>Applications of Ultrasound
A girl drops a ball from a height h=20 m. It strikes the ground elastically and returns to her hand. An echo of the thud of the ball striking the ground is produced from a nearby cliff. The echo is head at exactly the same moment when the ball returns to the girl's hand. (Take g = 10 ms-2  and vsound=350 ms-1). The distance of the cliff from the girls is close to:
MEDIUM
Science>Physics>Sound>Applications of Ultrasound
Name the system which enables us to locate underwater objects by transmitting ultrasonic waves and detecting the reflecting impulse.
EASY
Science>Physics>Sound>Applications of Ultrasound
What is the difference between reverberation and echo?
EASY
Science>Physics>Sound>Applications of Ultrasound
Sound signal from a ship floating in water hits the bottom of the sea and reflects back to the ship after 6 s. Speed of sound in water is 1500 m s-1. Calculate the depth of the sea.
EASY
Science>Physics>Sound>Applications of Ultrasound
A man standing in front of a vertical cliff fires a gun. He hears the echo after 3.5 sec. On moving closer to the cliff by 84 m, he hears the echo after 3 sec. Calculate the distance of the cliff from the initial position of the man.
HARD
Science>Physics>Sound>Applications of Ultrasound
A pendulum  has a frequency of 4 vibrations per second. An observer starts the pendulum and fires a gun simultaneously. He hears the echo from the cliff after 6 vibrations of the pendulum. If the velocity of sound in air is 340 ms-1, find the distance between the cliff and the observer. 
MEDIUM
Science>Physics>Sound>Applications of Ultrasound
State one use of reflection of sound.
EASY
Science>Physics>Sound>Applications of Ultrasound
How is ultrasound used in detection of fetal abnormalities?
MEDIUM
Science>Physics>Sound>Applications of Ultrasound
What is the name of the device which is used to find the depth of sea (or ocean) by using ultrasonic sound waves?
EASY
Science>Physics>Sound>Applications of Ultrasound
Write the full name of 'SONAR'.
EASY
Science>Physics>Sound>Applications of Ultrasound
Using sonar, sound pulses are emitted at the surface. The pulses, after being reflected from the bottom, are detected. If the time interval from the emission to the detection of the sound pulses is 2 seconds, find the depth of the water. (take velocity of sound through water, v=1500 m/s)
EASY
Science>Physics>Sound>Applications of Ultrasound
Why do we prefer ultrasonic frequencies for real-life applications?
MEDIUM
Science>Physics>Sound>Applications of Ultrasound
How is an ultrasound scan for the foetus (unborn baby) better than X-ray?
EASY
Science>Physics>Sound>Applications of Ultrasound
Give one use of ultrasound in industry and one in hospitals.