BROADCAST QUIZ 4&5

Sound is produced by _______ that set into motion radiating waves of compression and rarefaction.

• propulsion

• generators

• vibrations

• frequencies

Human being are capable of hearing frequencies within the range of __________.

• 20 Hz - 20 kHz

• 2 Hz - 20 Hz

• 20 Hz - 200 kHz

• 200 Hz - 20 kHz

The number of cycles that a vibration completes in one second is expressed as its _________.

• frequency

• amplitude

• wavelength

• dynamic

Amplitude which is the size of a sound wave, is measured in ___________.

• decibels

• Hz

• Kg

• Lambda

The threshold of pain for a human being is ______

• 100 dB SPL

• 113 dB SPL

• 128 dB SPL

• 140 dB SPL

What are sounds that are above the human hearing range called?

• Infrasonic

• Subsonic

• Extrasonic

• Supersonic

Which of the following devices uses the generator effect?

• Loudspeaker

• Microphone

• Headphones

In a moving microphone, what causes the coil of wire to move in a magnetic field?

• Alternating current

• The sound waves hitting the diaphragm attached to the coil.

• The vibrations hitting the diaphragm attached to the coil

• Direct Current

What factor of the ac current affects the frequency of the sound wave produced by a loud speaker?

• Wavelength

• Frequency

• Amplitude

• pitch

A sound of frequency 2000 Hz is emitted by a source which moves away from an observer and moves towards a cliff at a speed of 20 m/s

Compute the frequency of sound heard by the observer reflected off the cliff.

Assume the speed of sound in air is 343 m/s

(Round off the answer to whole number)