A:c(Na+)等于c(CO32-)与c(HCO3-)之和
B:c(HCO3-) 等于c(CO32-)
C:c(HCO3-) 略大于c(CO32-)
D:c(HCO3-) 略小于c(CO32-)
一闭合线圈有50匝,总电阻为20Ω,穿过它的磁通量在0.1s内由8×10-3Wb 增加到1.2×10-2Wb,则线圈中的感应电动势E=____V,线圈中的平均电流强度I=____A.
Jim tried his best to raise his spirits though he failed the exam.