An electric dipole with dipole moment p- -3i-4j- 10 -30 C-m is placed in an electric field E- -4000- N-C- An external agent turns the dipole and its dipole moment becomes -4- -3- -10-30C-m- The work done by the external agent is equal to-

Two equal and opposite charges of $4 \times 10^{- 8}$ C when placed $2 \times 10^{- 2} c m$ away, form a dipole. If this dipole is placed in an external electric field of $4 \times 10^{8}$ newton/coulomb, the value of maximum torque and the work done in rotating it through $180^{\circ}$ will be

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An electric dipole with dipole moment →p=(3i+4j)×10−30C−m is placed in an electric field →E=4000^i(N/C). An external agent turns the dipole and its dipole moment becomes (−4^i+3^j)×10−30C−m. The work done by the external agent is equal to:

The correct option is B −4×10−27JWork done =Uf−Ui=(−→p.→E)f−(−→p.→E)i=−(−16×10−27)−(−12×10−27)=−4×10−27J

An electric dipole with dipole moment $\to p = (3 i + 4 j) \times 10^{- 30} C - m$ is placed in an electric field $\to E = 4000^i (N / C)$ . An external agent turns the dipole and its dipole moment becomes $(- 4^i + 3^j) \times 10^{- 30} C - m$ . The work done by the external agent is equal to:

The correct option is B $- 4 \times 10^{- 27} J$
Work done $= U_{f} - U_{i} = {(- \to p . \to E)}_{f} - {(- \to p . \to E)}_{i}$
$= - (- 16 \times 10^{- 27}) - (- 12 \times 10^{- 27})$
$= - 4 \times 10^{- 27} J$