NEET 2015 Physics Capacitors and Dielectrics MCQ Question
A parallel plate capacitor of capacitance C is connected to a cell of emf V and then disconnected from it. A dielectric slab of dielectric constant k, which can just fill the air gap of the capacitor, is now inserted in it. Which of the following is incorrect?
The potential difference between the plates decreases k times.
The energy stored in the capacitor decreases k times.
The change in energy stored is 1/2 CV² (k - 1).
The charge on the capacitor is not conserved.
Correct Answer
Detailed Explanation
When the capacitor is disconnected, the charge remains constant. The potential difference and energy change due to the dielectric, but the charge is conserved.
Found an issue with this question?
Related Questions
More from Electrostatics
A conducting sphere of radius R carrying charge Q lies inside an uncharged conducting shell of radius 2R. If they are joined by a metal wire, the amou...
Assertion : Electric potential of earth is taken zero. Reason : No electric field exists on earth surface.
The equivalent capacitance of the system shown in the following circuit is: