Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NEET 2025
Exam
NEET
Year
2025
Subject
Physics
Chapter
Electromagnetic Waves

NEET 2025 · Physics · Electromagnetic Waves

A parallel plate capacitor made of circular plates is being charged...

A parallel plate capacitor made of circular plates is being charged such that the surface charge density on its plates is increasing at a constant rate with time. The magnetic field arising due to displacement current is :

Options

  1. Azero at all places
  2. Bconstant between the plates and zero outside the plates
  3. Cnon-zero everywhere with maximum at the imaginary cylindrical surface connecting peripheries of the plates
  4. Dzero between the plates and non-zero outside

Correct answer

C. non-zero everywhere with maximum at the imaginary cylindrical surface connecting peripheries of the plates

Step-by-step solution

Id=ϵ0dϕedt=ϵ0ddt(EAcos⁡0∘)Id=ϵ0AdEdt∵E=σϵ0;Id=ϵ0Addt(σϵ0)⇒Id=A(dσdt)= constant \begin{aligned} & I_d=\epsilon_0 \frac{d \phi_e}{d t}=\epsilon_0 \frac{d}{d t}\left(E A \cos 0^{\circ}\right) \\ & I_d=\epsilon_0 A \frac{d E}{d t} \\ & \because E=\frac{\sigma}{\epsilon_0} ; I_d=\epsilon_0 A \frac{d}{d t}\left(\frac{\sigma}{\epsilon_0}\right) \\ & \Rightarrow I_d=A\left(\frac{d \sigma}{d t}\right)=\text{ constant } \end{aligned} Also BB due to IdI_d is max m{ }^m at surface of imaginary cylinder
Practice Electromagnetic Waves on Quantrex Academy →

More from Electromagnetic Waves

A parallel-plate capacitor of 50\ contains a dielectric slab of constant ( k ) with the… MHT CET Medical 2026An electromagnetic wave travelling in a lossless dielectric medium having a dielectric… NEET 2026Match List I with List II : List I (Electromagnetic wave) List II (Production) A.… NEET 2026The following table presents the part of the electromagnetic spectrum and their… NEET 2026The electric field in a plane electromagnetic wave is given by E_z=60 (5 x+1.5 × 10^9 t)… NEET 2025A parallel plate capacitor is charged by connecting it to a battery through a resistor.… NEET 2024The electromagnetic radiation which has the smallest wavelength are NEET 2024The property which is not of an electromagnetic wave travelling in free space is that: NEET 2024 Full Electromagnetic Waves list All NEET PYQs