Question

對(duì)于電場(chǎng)中A、B兩點(diǎn),下列說(shuō)法正確的是(    )

A.電勢(shì)差的定義式U_AB=,說(shuō)明兩點(diǎn)間的電勢(shì)差U_AB與電場(chǎng)力做功W_AB成正比,與移動(dòng)電荷的電荷量q成反比

B.把正電荷從A點(diǎn)移到B點(diǎn)電場(chǎng)力做正功,則有U_AB＞0

C.電勢(shì)差的定義式U_AB=中,U_AB與移動(dòng)的電荷量q無(wú)關(guān)

D.電場(chǎng)中A、B兩點(diǎn)間的電勢(shì)差U_AB等于把正電荷q從A點(diǎn)移動(dòng)到B點(diǎn)時(shí)電場(chǎng)力所做的功

Answer 1

BC    解析：電場(chǎng)中兩點(diǎn)之間的電勢(shì)差是一個(gè)定值,與電場(chǎng)力對(duì)檢驗(yàn)電荷做的功無(wú)關(guān),故選項(xiàng)A錯(cuò),C對(duì).U_AB=知,電場(chǎng)力做正功,則電勢(shì)差為正,即選項(xiàng)B對(duì).電場(chǎng)中A、B兩點(diǎn)間的電勢(shì)差U_AB等于把單位正電荷q從A點(diǎn)移動(dòng)到B點(diǎn)時(shí)電場(chǎng)力所做的功,故選項(xiàng)D錯(cuò).