Mặt phẳng rất rộng, tích điện đều Q > 0. So sánh cường độ điện trường E do
mặt phẳng gây ra tại các điểm A, B, C.
A. EA > EB > EC.
B. EA = EB = EC.
C. EA = EB > EC.
D. EA = EB < EC

It is really hard for me right know

The electric potential v is constant everywhere within a certain region of space. which statement below is true? the choices are: the electric field is also constant (but not zero) within the region. a charged particle placed within the region will experience an electric force. the electric field is zero everywhere within the region. the electric field varies from place to place within the region.

How can waves travel through ground?