Bennett Mechanical Test Acoustics and Optics 5

Question 1

The change in pitch as a moving siren passes you is called the:

Accepted Answer

Doppler effect

Answer

The Doppler effect changes perceived frequency as a sound source moves toward or away.

Question 2

Total internal reflection in a fiber-optic cable keeps light:

Accepted Answer

Trapped inside the fiber

Answer

Light striking the fiber wall at a steep angle reflects entirely, staying inside the cable.

Question 3

When two sound waves combine to produce a louder sound, this is:

Accepted Answer

Constructive interference

Answer

Constructive interference occurs when waves align in phase, increasing amplitude and loudness.

Question 4

A camera lens focuses an image onto the sensor by:

Accepted Answer

Refracting light to a focal point

Answer

The convex camera lens refracts incoming light to converge a sharp image at the sensor.

Question 5

Which of these has the highest frequency and is inaudible to humans?

Accepted Answer

Ultrasound

Answer

Ultrasound has frequencies above 20,000 Hz, beyond the range of human hearing.

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