Test 2: Echo, Refraction, Diffraction, Infrasound, Ultrasound and Acoustics

Question 1

An echo is produced due to:

• Arefraction of sound waves
• Breflection of sound waves
• Cdiffraction of sound waves
• Dabsorption of sound waves

Question 2

Why is acoustic protection important in building design?

• ATo increase noise pollution
• BTo reduce echo and improve sound quality
• CTo amplify sound
• DTo increase the speed of sound

Question 3

For a normal person, the audible frequency range for sound waves lies between:

• A10 Hz and 10 kHz
• B20 Hz and 20 kHz
• C25 Hz and 25 kHz
• D30 Hz and 30 kHz

Question 4

When sound waves hit a surface and bounce back into the same medium, the phenomenon is called:

• Aan echo or reflection of sound
• Brefraction
• Cdiffraction
• Dabsorption

Question 5

To hear a distinct echo, the reflected sound must reach us after at least:

• A0.1 seconds
• B1 second
• C0.01 seconds
• D10 seconds