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~
Phy 高手請答
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.
without obstacle is necessary .
However ,radio signals can be received easily by antenna sheltered by obstacles. Explain.
回答 (3)
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
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
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
收錄日期: 2021-04-20 16:20:53
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