2. An electric dipole with dipole moment 5 × 10⁻⁶ Cm is aligned with the direction of a uniform electric field of magnitude 4 × 10⁵ N/C. The dipole is then rotated through an angle of 60° with respect to the electric field. The change in the potential energy of the dipole is:
Given p = 5 × 10⁻⁶ Cm, E = 4 × 10⁵ N/C, θᵢ = 0°, θf = 60°
ΔU = Uf − Ui = −pEcosθf + pEcosθᵢ = pE(cos0° − cos60°) = 5 × 10⁻⁶ × 4 × 10⁵ × (1 − 0.5) = 1.0 J
ΔU = Uf − Ui = −pEcosθf + pEcosθᵢ = pE(cos0° − cos60°) = 5 × 10⁻⁶ × 4 × 10⁵ × (1 − 0.5) = 1.0 J
Electric Dipole Potential Energy – NEET PYQ Importance
NEET PYQs play a vital role in understanding exam patterns and frequently tested physics concepts. This particular MCQ targets a key idea from electrostatics — the potential energy change of an electric dipole in a uniform electric field.
These kinds of rotational dipole problems help develop deeper problem-solving skills, especially in energy-based reasoning. PYQ practice ensures you don’t just memorize formulas but also learn how to apply them correctly under pressure. For any NEET aspirant, solving such standard questions is a smart way to score higher in Physics.
