题目10单选题
一空气平行板电容器,极板面积为S,两极板相距为d,电容器两端电压为U,则电容器极板上的电量q= .若将厚度为d/2的金属板平行插入电容器内,保持电压U不变,则极板上电量增加Δq= <img src="https://tihai-oss-cloud.itihey.com/img/6e8d9272b11f5fcef242f39d90ca29aa.png">A. <img src="https://tihai-oss-cloud.itihey.com/img/c81f8924e08942e54a53ee54b9ffa9c2.png">B. <img src="https://tihai-oss-cloud.itihey.com/img/1e8558c79cff575d0c9aa81a76844e51.png">C. <img src="https://tihai-oss-cloud.itihey.com/img/fc3cd2069c72bf8fcb75b1c0bcda134d.png">D. <img src="https://tihai-oss-cloud.itihey.com/img/570dbf26d10b358f86b90d68496d5a6c.png">