When these electromagnetic waves escape from the conductor into space, they are said to be radiated by the conductor, hence the name radio waves.

Consider an interference between two waves. At a certain position if the vibrations caused by two waves are in phase, they make a destructive interference.? 正确|错误

How is television different from radio A: Sound is changed into electromagnetic waves. B: Light is changed into electromagnetic waves. C: Both sound and light are changed into electromagnetic waves. D: Either sound or light is changed into electromagnetic waves.

Waves are beautiful to look at, but they can destroy ships at sea, as well as houses and buildings near the shore. What causes waves? Most waves are caused by winds blowing over the surface of the water. The sun heats the earth, causing the air to rise and the winds to blow. The winds blow across the sea, pushing little waves into bigger and bigger ones. The size of a wave depends on how strong the wind is, how long it blows, and how large the body of water is. In a small bay(海湾) big waves will never build up. But at sea the wind can build up huge and powerful waves. A rule says that the height of a wave (in meters) will usually be no more than one-tenth of the wind’s speed (in kilometers). In other words, when the wind is blowing 120 kilometers per hour, most waves will be about twelve meters. Of course, some waves may combine to form huge waves that are much higher. In 1933 the United States Navy( 海军) reported the largest measured wave in history. I t rose in the Pacific Ocean to a height of thirty-four meters.

The glass wall _______ heat waves.

electromagnetic waves

Which type of earthquake wave is a compressional wave? A: P-waves B: surface waves C: long waves D: S-waves

The British used radio waves because they ________.

The Elastic waves include P-wave and S-wave.

Keeping your laptop _______ all the time will kill its battery faster. A: made waves B: plugging in C: plugged in D: making waves