一、電壓表怎么看測量對象

判斷電(dian)(dian)(dian)(dian)壓表測量的(de)是(shi)電(dian)(dian)(dian)(dian)路(lu)中(zhong)哪一(yi)部分(fen)(fen)的(de)電(dian)(dian)(dian)(dian)壓，這類題目在練習和(he)試題中(zhong)頻頻出(chu)(chu)現，由于電(dian)(dian)(dian)(dian)壓表與用(yong)電(dian)(dian)(dian)(dian)器并(bing)聯，在串聯電(dian)(dian)(dian)(dian)路(lu)中(zhong)，不(bu)論是(shi)實物電(dian)(dian)(dian)(dian)路(lu)還是(shi)形式(shi)有變(bian)化的(de)電(dian)(dian)(dian)(dian)路(lu)圖中(zhong)，學(xue)生(sheng)往往不(bu)能快速準確(que)地判斷電(dian)(dian)(dian)(dian)壓表究(jiu)竟測量的(de)是(shi)哪一(yi)部分(fen)(fen)的(de)電(dian)(dian)(dian)(dian)壓，基于上述原因，給出(chu)(chu)以下方(fang)法：

1、短路法

電壓表去掉，假設用(yong)導線接該(gai)位置，若(ruo)此時某些用(yong)電器或(huo)電源被短路，則(ze)這些用(yong)電器或(huo)電源即為(wei)該(gai)電壓表測(ce)量的(de)對象(xiang)。

2、去源法

“去掉”電(dian)源(yuan)（用手捂(wu)住(zhu)電(dian)源(yuan)），再(zai)看電(dian)壓(ya)表與(yu)哪(na)部(bu)分構成閉合回路(lu)，那(nei)么(me)電(dian)壓(ya)表測的就是那(nei)部(bu)分電(dian)路(lu)的電(dian)壓(ya)。

3、滑線法

電(dian)壓表(biao)兩端沿著連(lian)接(jie)的導(dao)線(xian)滑動到用電(dian)器或電(dian)源(yuan)兩端。（能跨(kua)過元件：開關、電(dian)流(liu)表(biao)。不能跨(kua)過元件：電(dian)源(yuan)、用電(dian)器、電(dian)壓表(biao)）。

4、特殊說明

（1）電壓表接在電路中相當于該處開(kai)路。

（2）電流表接(jie)在電路中相當(dang)于一根(gen)導(dao)線。

（3）電壓(ya)表與用電器(qi)串聯(lian)拖后接在(zai)電源兩端，電壓(ya)表測量的(de)是電源電壓(ya)。

二、電壓表測量對象短路會怎么樣

被測(ce)(ce)試(shi)的(de)(de)(de)用電(dian)(dian)(dian)(dian)(dian)器(qi)短路(lu)的(de)(de)(de)時候，電(dian)(dian)(dian)(dian)(dian)壓(ya)表(biao)顯示為零，被測(ce)(ce)試(shi)的(de)(de)(de)用電(dian)(dian)(dian)(dian)(dian)器(qi)斷(duan)路(lu)的(de)(de)(de)時候，通常很多人會認為被測(ce)(ce)試(shi)是(shi)開(kai)路(lu)電(dian)(dian)(dian)(dian)(dian)壓(ya)。實(shi)際并不準確，只有輸入電(dian)(dian)(dian)(dian)(dian)壓(ya)與(yu)被測(ce)(ce)試(shi)的(de)(de)(de)用電(dian)(dian)(dian)(dian)(dian)器(qi)直接相連的(de)(de)(de)情況下，斷(duan)路(lu)之(zhi)后，電(dian)(dian)(dian)(dian)(dian)壓(ya)表(biao)測(ce)(ce)試(shi)出來才(cai)是(shi)開(kai)路(lu)電(dian)(dian)(dian)(dian)(dian)壓(ya)。但是(shi)如果(guo)輸入電(dian)(dian)(dian)(dian)(dian)壓(ya)與(yu)被測(ce)(ce)試(shi)的(de)(de)(de)用電(dian)(dian)(dian)(dian)(dian)器(qi)之(zhi)間有其他感容(rong)電(dian)(dian)(dian)(dian)(dian)子元(yuan)件的(de)(de)(de)話，受(shou)到(dao)感容(rong)電(dian)(dian)(dian)(dian)(dian)子元(yuan)件的(de)(de)(de)影響(xiang)，測(ce)(ce)試(shi)出來的(de)(de)(de)實(shi)際是(shi)頻率電(dian)(dian)(dian)(dian)(dian)壓(ya)。