空气与介质
的分界面为z=0的平面，已知空气中的电场强度为
,则介质中的电场强度
：()
A:
B:
C:
D:
的分界面为z=0的平面，已知空气中的电场强度为,则介质中的电场强度：()A:
B:
C:
D:
举一反三
- 已知Z变换Z<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/94487389db974f98b2d38b947ec20d83.png" >，收敛域<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/56b4868c286b4b48a8cec67f9f766670.png" >，则逆变换x（n）为()。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/547656863c8b459da97c366d9321ef13.png" > B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/d3572493bf964e2d92fde49d59b632af.png" > C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/c4aacba69e0445b0ad4db797b3c86d53.png" > D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/b9af7d9dccb3446595a3a587492eb92a.png" >
- 已知信号<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/82c317e53c6941b59567bc236a6ec9ba.png" >，则奈奎斯特取样频率fs为()。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/7f3cd88d635b4fe0871233447ea5494b.png" > B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/53752d34e4c64504bc111e280262e228.png" > C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/50d5151b1d3f406185372b2ac9f19f93.png" > D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/ad47ea06d5aa4270a8e0089425f0bf6d.png" >
- 理想低通滤波器的传输函数<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/980b5b2a8d7044b697bc516003ea3acb.png" >是()。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/9a82e2e4ff27470da538512097ee6438.png" > B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/c079877bd52d471db3cd6e163f62adbb.png" > C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/52aa9898f12641d797c40e4d118bd733.png" > D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/a7815d7407f34172aeef470a6adc5f47.png" >
- 单边拉普拉斯变换<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/423a53f9b3bf40989454133dbce2d262.png" >的原函数等于（）。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/301dd2111ac64b0e8217cba94ba1a1ab.png" > B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/9772eee6eab34c208eba55009d00041b.png" > C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/42bfb5f864e34b5ca02a2a1cc9d9c71b.png" > D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/659eef6ba24b490191772fe51bab3c9a.png" >
- 为求方程<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/ce3ea4db5573483a89d1d732d75e1036.png" >在<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/31ea0f26a7064e83856e0c3a268aa9c5.png" >附近的根，则使得迭代格式<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/2cb16d8f43544cca8adc73fc7dce0dff.png" >一定局部收敛的迭代函数为() A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/c52ae5e1d8ca4c51ac71ad740e0bb231.png" > B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/54a5d832d2544db7905c50c2c7287f09.png" > C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/cdecd203bf8049c5b3faccb7e68a42aa.png" > D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202002/4a5e9a33f10e4d489df882c59db1d545.png" >