《信息的传递》单元测试题二（参考答案）

信息的传递单元测试题二（参考答案）DIV.MyFav_1308035400961 P.MsoNormalTEXT-JUSTIFY: inter-ideograph; FONT-SIZE: 10.5pt; FONT-FAMILY: Times New Roman; TEXT-ALIGN: justifyDIV.MyFav_1308035400961 LI.MsoNormalTEXT-JUSTIFY: inter-ideograph; FONT-SIZE: 10.5pt; FONT-FAMILY: Times New Roman; TEXT-ALIGN: justifyDIV.MyFav_1308035400961 DIV.MsoNormalTEXT-JUSTIFY: inter-ideograph; FONT-SIZE: 10.5pt; FONT-FAMILY: Times New Roman; TEXT-ALIGN: justifyDIV.MyFav_1308035400961 P.MsoHeaderBORDER-RIGHT: medium none; PADDING-RIGHT: 0cm; BORDER-TOP: medium none; PADDING-LEFT: 0cm; FONT-SIZE: 9pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; LAYOUT-GRID-MODE: char; PADDING-TOP: 0cm; BORDER-BOTTOM: medium none; FONT-FAMILY: Times New Roman; TEXT-ALIGN: centerDIV.MyFav_1308035400961 LI.MsoHeaderBORDER-RIGHT: medium none; PADDING-RIGHT: 0cm; BORDER-TOP: medium none; PADDING-LEFT: 0cm; FONT-SIZE: 9pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; LAYOUT-GRID-MODE: char; PADDING-TOP: 0cm; BORDER-BOTTOM: medium none; FONT-FAMILY: Times New Roman; TEXT-ALIGN: centerDIV.MyFav_1308035400961 DIV.MsoHeaderBORDER-RIGHT: medium none; PADDING-RIGHT: 0cm; BORDER-TOP: medium none; PADDING-LEFT: 0cm; FONT-SIZE: 9pt; PADDING-BOTTOM: 0cm; BORDER-LEFT: medium none; LAYOUT-GRID-MODE: char; PADDING-TOP: 0cm; BORDER-BOTTOM: medium none; FONT-FAMILY: Times New Roman; TEXT-ALIGN: centerDIV.MyFav_1308035400961 P.MsoFooterFONT-SIZE: 9pt; LAYOUT-GRID-MODE: char; FONT-FAMILY: Times New RomanDIV.MyFav_1308035400961 LI.MsoFooterFONT-SIZE: 9pt; LAYOUT-GRID-MODE: char; FONT-FAMILY: Times New RomanDIV.MyFav_1308035400961 DIV.MsoFooterFONT-SIZE: 9pt; LAYOUT-GRID-MODE: char; FONT-FAMILY: Times New RomanDIV.MyFav_1308035400961 A:linkCOLOR: blue; TEXT-DECORATION: underlineDIV.MyFav_1308035400961 SPAN.MsoHyperlinkCOLOR: blue; TEXT-DECORATION: underlineDIV.MyFav_1308035400961 A:visitedCOLOR: purple; TEXT-DECORATION: underlineDIV.MyFav_1308035400961 SPAN.MsoHyperlinkFollowedCOLOR: purple; TEXT-DECORATION: underlineDIV.MyFav_1308035400961 PREFONT-SIZE: 10pt; FONT-FAMILY: Arial Unicode MSDIV.MyFav_1308035400961 DIV.Section1page: Section1DIV.MyFav_1308035400961 OLMARGIN-BOTTOM: 0cmDIV.MyFav_1308035400961 ULMARGIN-BOTTOM: 0cm一、选择题1-14：D D C A C C A C D A A D D D二、填空题15电磁16增大 等于 31085.71（“5.7”亦可 ）17机械能 电磁波18紫外线 红外线 X射线 无线电波19增强 减弱20电磁波 激21 三、简答与实验题22(1)收音机会发出”咔咔嚓嚓”的声音。这是因为导线头在锉面上滑动时，产生了变化的电流，向空中激起了电磁波。（2）开启冰箱门时会听到收音机也发出“咔咔嚓嚓”的声音23接收卫星传来的信号。光缆通信的主要优点：容量大，不怕雷击，不受电磁干扰，通信质量高，保密性好。(2)开、关日光灯时，产生了变化的电流，周围空间就存在电磁波，电视机接收以后，会在电视机