题目

为什么积分下限是R29、图示一均匀带电球体,总电荷为 +0, 其外部同心地罩一内、外半-|||-径分别为r1、r2的金属球壳.设无穷远处为电势零点,则在球壳内半径为-|||-r的P点处的场强和电势为:-|||-(A) =dfrac (Q)(4pi {varepsilon )_(0)(r)^2} , =dfrac (Q)(4pi {varepsilon )_(0)r} (B) E=0 , =dfrac (Q)(4pi {varepsilon )_(0)(r)_(1)}-|||-(C) E=0 , =dfrac (Q)(4pi {varepsilon )_(0)r} (D) E=0 , =dfrac (Q)(4pi {varepsilon )_(0)(r)_(2)}

为什么积分下限是R2

题目解答

答案

B. E=0 , $U=\dfrac {Q}{4\pi {\varepsilon }_{0}{r}_{1}}$