試題詳解

50. A cloud layer is 1000 m above the planet, with the area of 1x10⁶ m² , considered as the plates of a parallel-plate capacitor. If an electric field strength is greater than 3.0x10⁶ N/C, it causes lightning, what is the maximum charge the cloud can hold? (εo= 8.85 x 10^-12 C² /N•m2 )
(A) 28.55 C
(B) 26.55 C
(C) 24.55 C
(D) 22.55 C
(E) 20.55 C