⚛️ Physics · Electrostatic Potential and Capacitance · NEET & JEE

If dielectric of constant K is inserted in a parallel plate capacitor (isolated, constant charge Q), energy stored:

Answer: Decreases by factor K.

A Increases by K
B Decreases by factor K
C Stays same
D Increases by K2

Correct answer: B. Decreases by factor K

Explanation: With dielectric, C increases to KC. Q stays same (isolated). U = Q2/(2C). New U = Q2/(2KC) = U/K. Energy decreases.

Radial electric field lines and concentric red equipotential lines around a point charge (an electron), with field lines pointing inward

Field lines (radial) and equipotential lines (concentric circles) of a point charge. Equipotential surfaces are always perpendicular to the field lines. Image: Sjlegg, Public Domain, via Wikimedia Commons.

Concept context

Electric potential, equipotential surfaces, potential energy of charge systems, conductors, dielectrics, capacitors, combinations, and energy storage.

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If dielectric of constant K is inserted in a parallel plate capacitor (isolated, constant charge Q), energy stored:

Concept context

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