問題詳情

21.A dipole for which p

m is in a uniform field E

7 104 N /C  . What is the external workneeded to rotate the dipole from alignment with the field to angle 60°to the field?( cos60 o

0.5;sin 60o

0.9   )
(A)


(B)

 
(C)

 
(D)


(E)



參考答案