Identify the incorrect statement(s) among the following:
When a dielectric medium is introduced between the plates of a charged capacitor the electric field inside the dielectric changes due to polarisation. $E_0$ is the electric field between the plates of capacitor without dielectric and $E_p$ is the electric field due to polarisation.
(A) If a plate of dielectric constant k, thickness t is placed between the plates of a charged capacitor of area A of the plate and having distance d between the plates, then the new capacitance will be $Aε_0/(d-t(1+1/k))$
(B) The electric field between plates of the charged capacitor when the dielectric is introduced will be $E=(E_0-E_p)$
(C) Dilectric constant of the dielectric placed between plates of charged capacitor will be $k = E_0/(E_0-E_p)$
(D) Dielectric strength of the dielectric is the maximum value of the electric field which may be applied before its break down,
Choose the correct answer from the option given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → (A) only
(A) Incorrect — The correct formula for capacitance with a dielectric slab of thickness t and dielectric constant k partially filling the capacitor is more complex; the given formula $C = \frac{A\epsilon_0}{d - t(1+1/k)}$ is incorrect.
(B) Correct — Electric field inside dielectric $E = E_0 - E_p$ due to polarisation.
(C) Correct — Dielectric constant $k = \frac{E_0}{E_0 - E_p}$
(D) Correct — Dielectric strength is the maximum electric field before breakdown.
Incorrect statement: (A)