When a dipole placed parallel to electric field is rotating through ^c , the work done is W. The work done in rotating the dipole through ( 3 )^c is ( 0^ = 1 , 60^ = 1 2 , 180^ = -1 )

Step-by-step solution

Work done in rotating a dipole in a uniform electric field from angle ₁ to ₂ is given by W = pE( ₁ - ₂) . Initially, the dipole is parallel to the electric field, so ₁ = 0 . When rotated through , ₂ = . W = pE( 0 - ) = pE(1 - (-1)) = 2pE pE = W 2 When rotated through 3 , ₂ = 3 . W' = pE ( 0 - 3 ) = pE (1 - 1 2 ) = pE 2 Substituting pE = W 2 , we get: W' = 1 2 ( W 2 ) = W 4 Answer: W 4