正确答案:

题目：功率因数校正电路可使电网输入电流变为与输入电压幅度相同的正弦波。（ ）

解析：×

查看原题 点击获取本科目所有试题

举一反三的答案和解析：

[单选题]考虑GSM设备的带外抑制能力，线阵天线在GSM定向天线背部(定向天线主方向+/-120度外)，应要求?()

水平>=2m，垂直>=1m

[单选题]生产力中具有决定意义的因素是()，即第一生产力。

科学技术

[多选题]【An overall cellular network contains a number of different elements from the base transceiver station (BTS) itself with its antenna back through a base station controller (BSC), and a mobile switching centre (MSC) to the location registers (HLR and VLR) and the link to the public switched telephone network (PSTN). Of the units within the cellular network, the BTS provides the direct communication with the mobile phones. There may be a small number of base stations then linked to a base station controller. This unit acts as a small centre to route calls to the required base station, and it also makes some decisions about which of the base station is best suited to a particular call. The links between the BTS and the BSC may use either land lines of even microwave links. Often the BTS antenna towers also support a small microwave dish antenna used for the link to the BSC. The BSC is often co-located with a BTS. The BSC interfaces with the mobile switching centre. This makes more widespread choices about the routing of calls and interfaces to the land line based PSTN as well as the HLR and VLR.】 From the paragraph above, in a cellular network, the （98） can provide direct communication with a mobile phone, the （99） acts as a small centre to route calls to the required base station, and it also makes some decisions about which of the base station is best suited to a particular call.（100） can be used to link the BSC with related BTS。

BTS

MS

VLR

解析：B,C,D

[多选题]关于处理增益说法正确的是()

处理增益与调制方式、编码方式、扩频因子有关

TD处理增益等于Eb/No减去C/I

解析：A, C

[单选题]用户为了防止自家电话被别人盗打，可以使用（）业务。

呼出限制

[单选题]下列选项中，（49）属于单模光纤的常用通信窗口波长。

1310nm

[单选题]下列选项中，不属于数据通信网服务质量指标的是（ ）。

传播时延

[单选题]虚拟网业务是电信运营商在市话交换机公网上开发的具有（ ）服务功能的电话业务。

用户小交换机

[单选题]数字数据网DDN是采用（）信道来传输数据信息的数据网。

数据