Sound and the Doppler Effect Quiz

What is the Doppler Effect?

• A change in sound intensity due to distance

• A type of sound wave

• A measure of sound loudness

• An apparent change in frequency due to relative motion

What is the threshold of hearing in W/m²?

• 1 x 10^-9

• 1 x 10^-12

• 1 x 10^-15

• 1 x 10^-6

What unit is used to measure sound intensity level?

• Hertz

• Decibels

• Joules

• Watts

What is the relationship between loudness and intensity?

• No relationship

• Roughly proportional to the logarithm of intensity

• Inversely proportional

• Directly proportional

What type of wave is a sound wave?

• Electromagnetic wave

• Longitudinal wave

• Transverse wave

• Surface wave

What is the typical speed of sound in air?

• 340 m/s

• 300 m/s

• 400 m/s

• 360 m/s

What happens to the frequency of sound as the source approaches the observer?

• It decreases

• It becomes inaudible

• It remains the same

• It increases

What is the formula for calculating intensity level in decibels?

• β = 10 LOG(I0/I)

• β = 20 LOG(I/I0)

• β = 5 LOG(I/I0)

• β = 10 LOG(I/I0)

If a sound source is moving away from an observer, what happens to the frequency heard by the observer?

• It becomes zero

• It remains constant

• It increases

• It decreases

What is the frequency range of audible sound for humans?

• 0 Hz to 20 Hz

• 20 Hz to 20,000 Hz

• 20,000 Hz to 20 kHz

• 0 Hz to 20 kHz