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👨🏻‍🏫 學術台其他 - 科學

用戶109462

2007-03-28 8:56 am

1. To receive TV signals , an antenna pointing directly towards the transmitting station
without obstacle is necessary .
However ,radio signals can be received easily by antenna sheltered by obstacles. Explain.

更新1:

我想問下呢~咁 radio signals 係EM wave ,咁TV signals 係咩wave? 可唔可以利用個d waves ge 特性去解釋呢條題目? plz~

回答 (3)

用戶141127

2007-04-01 8:00 am

✔ 最佳答案

咁首先呢你就要明白

WAVE LENTH 大= DIFFRACTION RATE 大

你諗下光同聲音就明,光我WAVELENGTH好短,SO佢會集中過SOUND,
咁其實 EM WAVE有好多隻, TV SIGNAL都係,只係唔同FREQUENCY唔同WAVELENTH 但SPEED一樣,EM WAVE的SPEED係 3X10^6MS^-1

因為RADIO的WAVE LENGTH大,SO DIFFRACT 得大D, SO 在有OBSTACLES的情況都可以DIFFRACT 大到收到SIGNAL

參考: ME

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用戶95367

2007-03-29 2:14 am

This because the degree of diffraction. When the obstacles are available, the gap is wider and therfore the diffraction effect increases.

參考: me

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[匿名]

2007-03-28 9:16 am

Since radio wave has a longer wave length so it would diffract more when something is blocking it. And raio signals can also be received easily by antenna sheltered by obstacles

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收錄日期: 2021-04-20 16:20:53
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