如图<img src="https://zk.995w.com/lqwvjeImg/2e/2eddd9242a81accd964bcc6254ad5327.png"style="width:105px;height:112px;">所示,半径为R的均匀带电球面,总电荷为Q,设无穷远处的电势为零,则球内距离球心为r的P点处的电场强度的大小和电势为:( )<br>· E=0,<img src="https://zk.995w.com/lqwvjeImg/ea/eaa649b062e81b03d6357c4d18798977.png"style="width:75px;height:45px;">.<br>· E=0,<img src="https://zk.995w.com/lqwvjeImg/99/99fa5325ba8e887962c51dd84802b661.png"style="width:78px;height:45px;">.<br>· <img src="https://zk.995w.com/lqwvjeImg/6b/6b9f9616df6b215c05a9454becbea2b8.png"style="width:81px;height:45px;">,<img src="https://zk.995w.com/lqwvjeImg/ea/eaa649b062e81b03d6357c4d18798977.png"style="width:75px;height:45px;"> .<br>· <img src="https://zk.995w.com/lqwvjeImg/6b/6b9f9616df6b215c05a9454becbea2b8.png"style="width:81px;height:45px;">,<img src="https://zk.995w.com/lqwvjeImg/7f/7f2f3d54fef22ee5ab20b4deb7e6f38a.png"style="width:78px;height:45px;">.