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Saturday, 31 October

JEE Main 2021 · PhysicsNumerical answerNumerical valueHardMulti-step

JEE Main 17 March 2021, Shift 1, Physics Q25

Question 25 of 90 in this shift, Physics question 25 of 30, Section B.

A parallel plate capacitor whose capacitance C is 14 pF is charged by a battery to a potential difference V = 12 V between its plates. The charging battery is now disconnected and a porcelin plate with k = 7 is inserted between the plates, then the plate would oscillate back and forth between the plates with a constant mechanical energy of __________ pJ. (Assume no friction)

Official answer

864

NTA final key.

Chapter
Electrostatic Potential and Capacitance
Topic
Dielectrics
Idea tested
Dielectric with Battery Disconnected

Same idea in other shifts

Asked 3× in all
  1. 4 Apr 2024, Shift 2 · Q60A parallel plate capacitor of capacitance 12.5 pFpF is charged by a battery connected between its plates to potential difference of 12.0…MediumNumerical value
  2. 25 Jul 2022, Shift 2 · Q58Two parallel plate capacitors of capacity C and 3C are connected in parallel combination and charged to a potential difference 18 V. The…MediumNumerical value

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.