Science 8 Wireless Speaker Pre-Test

How does the total amount of information differ between an analog and a digital signal?

• A digital signal has more information because it has more values than an analog signal

• A digital signal has more information because it has fewer values than an analog signal.

• An analog signal has more information because it has more values than a digital signal.

• An analog signal has more information because it has fewer values than a digital signal.

Why do most modern devices use digital signals?

• Digital signals contain more information than analog signals.

• Digital signals are more reliable over long distances than analog signals.

• Analog signals contain more information than digital signals.

• Analog signals are more reliable over long distances than digital signals.

A transmitter on the moon emits sound and light waves to a receiver on Earth. The light waves are picked up by the receiver but sound waves are not. This happens because

• The atmosphere absorbs sound.

• Sound gets scattered before it reaches Earth.

• Sound takes a very long time to cover the distance.

• 1. Sound cannot travel through the vacuum.

Which part of the longitudinal wave shown above represents one wavelength?

• Part A

• Part B

• Part C

• Part D

The diagram above shows a triangular wave. Which lettered part represents the amplitude of the wave?

• Part A

• Part B

• Part C

• Part D

Plucking a guitar string creates a wave whose motion is perpendicular to the downward force on the strings. The movement of the string is an example of a .

• Longitudinal wave

• Microwave

• Light wave

• Transverse wave

Select the phrases below that are characteristics of sound waves. (NOTE: select more than one answer.)

• A. Can cause objects to vibrate

• B. Always travels at the same speed

• D. Can travel through any type of matter

• C. Causes molecules to increase in size

• F. Travels faster in solids than through air.

Which material reflects the most light?

• Wax paper

• Aluminum foil

• Plastic wrap

• Brown paper

When a musician blows into a trumpet, a sound wave is formed that moves in the same direction as the musician’s breath. This is an example of a

• Microwave

• Light wave

• Longitudinal wave

• Transverse wave

Which would create the highest frequency?

• 20 waves in 10 seconds

• 30 waves in 5 seconds

• 100 waves in 10 seconds

• 5 waves in 5 seconds