14. There is an electric dipole in an external uniform E-field, as shown below.


where U(θ)=0 as θ=π/2.
(A) This expression is correct
(B) The negative sign after the second equal sign is wrong
(C) The negative sign after the last equal sign is wrong
(D) Both negative signs should be removed
(E) The dipole has a maximum potential cnergy when it is parallel to

答案:A
統計:A:0,B:0,C:0,D:0,E:0
難度:計算中