Sound

Why are walls of auditoriums often covered with sound-absorbing materials?

1. To increase echoes
2. To reduce reflection and improve sound quality
3. To increase the speed of sound
4. To increase the frequency of sound

Which characteristic of sound enables us to distinguish between the voices of different people?

1. Loudness only
2. Pitch only
3. Quality or timbre
4. Speed

Which instrument is used to detect underwater objects using sound waves?

1. Radar
2. SONAR
3. Telescope
4. Microscope

Sound with frequencies greater than 20,000 Hz is called

1. Audible sound
2. Infrasonic sound
3. Ultrasonic sound
4. Sonic boom

The audible range of frequencies for a healthy human being is approximately

1. 2 Hz to 200 Hz
2. 20 Hz to 20,000 Hz
3. 200 Hz to 2,000 Hz
4. 2,000 Hz to 200,000 Hz

The minimum distance required to hear a distinct echo in air is approximately

1. 5 m
2. 10 m
3. 17 m
4. 50 m

Which phenomenon is responsible for the production of an echo?

1. Refraction of sound
2. Reflection of sound
3. Diffraction of sound
4. Absorption of sound

Loudness of sound mainly depends on

1. Frequency
2. Speed
3. Amplitude
4. Wavelength

Which characteristic of sound determines its pitch?

1. Amplitude
2. Frequency
3. Speed
4. Wavelength

Which type of wave is a sound wave in air?

1. Transverse wave
2. Longitudinal wave
3. Electromagnetic wave
4. Surface wave

Sound cannot travel through

1. Air
2. Water
3. Steel
4. Vacuum

Sound requires which of the following to travel?

1. Vacuum
2. Medium
3. Sunlight
4. Electricity

Sound is produced due to

1. Reflection of light
2. Vibrations of objects
3. Heating of objects
4. Chemical reactions only