Echolocation

Q.

Give one reason for the use of ultrasonic waves for echo depth sounding.

Q. The ultrasonic waves from a bat hit a mosquito flying at a distance '$x$' and come back to the bat after $1.8s$. If the speed of the sound is $336m{s}^{-1},$ calculate the distance '$x$' of the prey.

1. $201.6m$
2. $604.8m$
3. $302.4m$
4. $151.2m$

Q. A hospital uses an ultrasonic scanner to locate tumors in a tissue. What is the wavelength of the sound in a tissue in which the speed of the sound is $1.7km/s$. the operating frequency of the scanner is $4.2MHz$. ( $1MHz={10}^{6}Hz)$

1. $4.05\times {10}^{-4}m$
2. $9.05\times {10}^{-4}m$
3. $6.05\times {10}^{-4}m$
4. $4.05\times {10}^{4}m$

Q. A dolphin echolocates its prey in $1.25\text{s}$. Assuming the prey is still, how long does it take for the dolphin to reach it, if it starts travelling at an average speed of $15\text{kmph}$? (Take the speed of sound in water to be $1400\text{m}{\text{s}}^{-1}$)

1. $4.5\text{min}$
2. $5.0\text{min}$
3. $3.5\text{min}$
4. $2.0\text{min}$

Q. Which of the following use echolocation?

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

Q.

Which technique is used by bats for navigation and location of food?

1. MRI

2. Reverberation

3. Echocardiography

4. Echolocation

Q. Which of the following techniques is used for identifying object location under water?

1. SONAR
2. RADAR
3. GPS
4. LASER

Q. Which of the following devices / organisms uses echolocation?

1. Bats

2. Dogs

3. SONAR

4. Telescope

Q. Which of these are hard-to-reach places where ultrasound can reach?

1. Spiral tubes
2. Oddly-shaped parts
3. Electronic computers
4. All of these