Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
MHT CET202619 April 2026Evening ShiftPhysicsCapacitanceActual

A parallel plate air capacitor has capacity 'C' farad, potential 'V' volt and energy 'E' joule. When the gap between the plates is completely filled with dielectric

Options

  1. AV increases, E decreases.
  2. BV decreases, E increases.
  3. Cboth V and E increase.
  4. Dboth V and E decrease.

Correct answer

D. both V and E decrease.

Step-by-step solution

Since the capacitor is isolated, the charge Q on the plates remains constant. The initial capacitance is C , potential is V = Q C , and energy is E = Q^2 2C . When a dielectric of dielectric constant K > 1 is introduced, the new capacitance becomes C' = KC . The new potential is V' = Q C' = Q KC = V K . Since K > 1 , V' The new energy is E' = Q^2 2C' = Q^2 2KC = E K . Since K > 1 , E' Therefore, both V and E decrease. Answer: both V and E decrease.

Practice Capacitance on Quantrex Academy →

More from Capacitance

A capacitor of capacitance 8 F is fully charged by connecting it to a source of 200V. It is then disconnected from the supply and connected to an uncharged capacitor of capacitance 2026What is the charge on 15 F in the circuit given? 2026A parallel plate capacitor has a uniform electric field ' E ' in the space between the plates. If the distance between the plates is ' d ' and area of each plate is ' A ', the ener 2026In the circuit shown in the figure, the potential difference across the 4 F capacitor is 2026A parallel plate air capacitor having area of each plate ' A ' and the distance between the plates ' d ' has uniform electric field E in the space between the plates. The energy st 2026In a parallel plate air capacitor of plate separation ' d ', a dielectric slab of thickness ' t ' is introduced between the plates. The capacitance becomes one-third of the origina 2026In an oscillating LC circuit the maximum charge on the capacitor is Q. When the energy is stored equally between the electric and magnetic fields, the charge on the capacitor (q) i 2026A slab of material of dielectric constant K has the same area as the plates of a parallel plate capacitor but has a thickness (4/5)d , where d is the separation of the plates. The 2026 Full Capacitance list All MHT CET PYQs