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NEET · Physics · STD 12 - 2. Electric potential and capacitance
A molecule of a substance has permanent dipole moment \(p\). A mole of this substance is polarised by applying a strong electrostatic field \(E\). The direction of the field is suddenly changed by an angle of \(60^{\circ} .\) If \(N\) is the Avogadro's number the amount of work done by the field is
- A \(\frac{1}{2}NpE\)
- B \(NpE\)
- C \(\;\frac{3}{2}NpE\)
- D \(2NpE\)
Answer & Solution
Correct Answer
(A) \(\frac{1}{2}NpE\)
Step-by-step Solution
Detailed explanation
\((\vec{U})=-\vec{p} \cdot \vec{E}=-p E \cos \theta\) \(W=\Delta U\)
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