Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
A parallel plate capacitor having capacitance 12pF is charged by a battery to a potential difference of 10V between its plates. The charging battery is now disconnected and a porcelain slab of dielectric constant 6.5 is slipped between the plates. The work done by the capacitor on the slab is
PhysicsCapacitanceJEE MainJEE Main 2019 (10 Jan Shift 2)
Options:
  • A  560 pJ
  • B 600 pJ
  • C 508 pJ
  • D 692 pJ
Solution:
1691 Upvotes Verified Answer
The correct answer is: 508 pJ

Initial energy of capacitor

Ui=12q2c
=12×120×12012=600 pJ

Since battery is disconnected so charge remain same. Final energy of capacitor

 Uf=12q2c k

=12×120×12012×6.5=92 pJ

W+Uf=Ui 
W=508 pJ

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.