Question

the dipole is aligned to field find the. find the work done in rotating it through the angle of 180degree
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Answer 1

Answer:

(I) Let an electric dipole is placed in a uniform electric field

E

, making an angle θ with the field ,

force on charge +q

F

+q

=+q

E

(along

E

)

force on charge −q

F

−q

=−q

E

(opposite to

E

)

as two equal and opposite forces are acting on the dipole therefore net force

F

=0

(ii) We know that work done in rotating a electric dipole from θ

1

to θ

2

, ( where θ

1

is the angle of dipole with electric field ) is given by ,

W=pE(cosθ

1

−cosθ

2

)

now given θ

1

=0,θ

2

=180

therefore W=pE(cos0−cos180)=2pE