=dfrac (Q)(4pi {varepsilon )_(0)r}-|||-(D) =dfrac (Q)(4pi {varepsilon )_(0)(r)^2
C-|||-R-|||-+Q-|||-(B) dfrac (qQ)(4pi {varepsilon )_(0)R} , -dfrac (qQ)(4pi {var
(B) dfrac (lambda )(2pi {varepsilon )_(0)a}. (C) dfrac (lambda )(4pi {varepsilon
dfrac (qQ)(4pi {varepsilon )_(0)l} C. dfrac (qQ)(2pi {varepsilon )_(0)l} D. -dfr
(B) dfrac (9)(4pi {varepsilon )_(0)a}-|||-(C) -dfrac (9)(8pi {varepsilon )_(0)a}
dfrac (qQ)(4pi {varepsilon )_(0)(d)_(1)} B. dfrac (qQ)(2pi {varepsilon )_(0)(d)_
17一个未带电的空腔导体球壳,内半径为R。在腔内离球心的距离为d处 -|||-A、 .-dfrac (9)(4pi {varepsilon )_(0)R}-||
U=0 (B) E=0 , =dfrac (9)(2pi {varepsilon )_(0)a} q q-|||-(C) =dfrac (q)(2pi {var
U=0-|||-(B) E=0 . =dfrac (q)(2pi {varepsilon )_(0)a}-|||-(C) =dfrac (q)(2pi {var
_(1)lt rlt (R)_(2) =dfrac ({Q)_(1)}(4{{Te)_(0)(r)^2}}-|||-D.两球面间的电势差 Delta U=dfr