\u65b0\u589e Microsoft Word \u6587\u4ef6 - 1 Electromagnetic waves are distinguished from sound waves The distinction is based on the fact that(a electromagnetic

# u65b0u589e Microsoft Word u6587u4ef6 - 1...

• 1

This preview shows page 1 out of 1 page.

1. Electromagnetic waves are distinguished from sound waves. The distinction is based on the fact that _____________ (a) electromagnetic waves can travel through materials and sound waves cannot. (b) electromagnetic waves can travel through a vacuum and sound waves cannot(c) electromagnetic waves have an infinite speed and sound waves have a finite speed (d) None of the above . 1 Electricity & Life| Test 1.Which one is NOT the application of ultrasonic wave? 3. When sound waves travel through air, the air particles _________________. (b) Vibrate but not in any fixed direction (c) Vibrate perpendicular to the direction of wave propagation (d) None of the above 4. Sound waves do not travel through ______________. (a) solids (b) liquids (c) water (d) vacuum 1.The frequency which is not audible to the human ear is ____________. (a) 500 Hz (b) 1 kHz (c) 5 kHz (d) 50 kHz 6. An ultrasonic wave is sent from a ship towards the bottom of the sea. It is found that the time interval between the sending and receiving of the wave is 1.6 s. What is the depth of the sea, if the velocity of soundin the seawater is 1400 m/s? (hint: transmission distance=velocity tiA (a) 1120 m (b) 560 m (c) 1400 m (d) 112 m