Sonar and Radar

Q. Which of the following use echolocation?

1. Bats
2. Dogs
3. SONAR
4. RADAR

Q.

A ship sends out ultrasound that returns from the seabed and is detected after $5s$. If the speed of ultrasound through seawater is $1600m/s$, what is the distance of the seabed from the ship?

1. 3.5 km

2. 4 km

3. 5 km

4. 2.5 km

Q.

An oil – tanker explodes in the sea. At that instant an aircraft and a submarine were present vertically above and below the oil – tanker respectively at equal distances from it. Find the ratio of the time taken by sound waves to reach them. (Speed of sound in air = 340 m/s. Speed of sound in sea water = 1520 m/s)

1. 6.40

2. 5.40

3. 4.47

4. 5.57

Q.

The process of determination of distance of target on the basis of time interval between the moment an ultrasonic impulse is transmitted and the moment its echo is received is called as:

1. Navigation

2. Ranging

3. Echo-ranging

4. Supersonic-ranging

Q.

In a sonar, ultrasonic waves are sent into the sea water and the reflected waves from a sunken ship are received after 2.0 s. If the velocity of waves in sea water is 1450 $m/s$, find the depth of the sunken ship.

1. 2900 m

2. 1450 m

3. 2800

4. 3000

Q.

Ultrasound is not used for:

1. Detecting cracks and flaws in metal blocks.

2. Internal imaging of human body.

3. Cleaning parts located in hard-to-reach places.

4. Diagnosing problem such as broken bones.

Q.

An object is $11km$ below sea level. A research vessel sends down a sonar signal to confirm this depth. After how long can it expect to get the echo? (Take the speed of sound in seawater as $1,520m/s$)

1. 14.47 s

2. 12.20 s

3. 11.13 s

4. 15.30 s

Q.

Ultrasonic waves are made to reflect from various parts of the heart and form the image of the heart. This technique is called___

Q. A ship sends a sonar wave to the sea bed which is flat and measured several times over a large area. One day the reflected sound wave takes longer time than in previous measurements. The possible reason is:

1. The frequency of the sonar wave, generated by the equipment is higher than previous measurements.
2. There is a solid object of large size in the path of sonar wave.
3. The loudness of the sonar wave, generated by the equipment is lower than previous measurement.
4. There is a huge air bubble in the path of sonar wave.

Q.

The device which uses ultrasonic waves to measure the distance, direction and speed of underwater objects is ___