Question 705057

Added on: Sep 19, 2026
SCQHARD

In a non-magnetic material with no free charges and no free currents, the permittivity ϵ\epsilon is a function of position. If E⃗\vec{E} represents the electric field and μ0,ϵ0\mu_0, \epsilon_0 are free space permeability and permittivity respectively, which one of the following expressions is correct?

(A)

∇2E⃗−μ0∂2(ϵE⃗)∂t2−1ϵ0∇(E⃗⋅∇ϵ)=0\nabla^2 \vec{E} - \mu_0 \frac{\partial^2(\epsilon\vec{E})}{\partial t^2} - \frac{1}{\epsilon_0} \nabla(\vec{E} \cdot \nabla\epsilon) = 0

(B)

∇2E⃗−μ0∂2(ϵE⃗)∂t2+1ϵ0∇(E⃗⋅∇ϵ)=0\nabla^2 \vec{E} - \mu_0 \frac{\partial^2(\epsilon\vec{E})}{\partial t^2} + \frac{1}{\epsilon_0} \nabla(\vec{E} \cdot \nabla\epsilon) = 0

(C)

∇2E⃗−μ0∂2(ϵE⃗)∂t2+∇(1ϵE⃗⋅∇ϵ)=0\nabla^2 \vec{E} - \mu_0 \frac{\partial^2(\epsilon\vec{E})}{\partial t^2} + \nabla(\frac{1}{\epsilon} \vec{E} \cdot \nabla\epsilon) = 0

(D)

∇2E⃗−μ0∂2(ϵE⃗)∂t2−∇(1ϵE⃗⋅∇ϵ)=0\nabla^2 \vec{E} - \mu_0 \frac{\partial^2(\epsilon\vec{E})}{\partial t^2} - \nabla(\frac{1}{\epsilon} \vec{E} \cdot \nabla\epsilon) = 0

Free Exam

Boost Your Exam Preparation!

Move beyond just reading solutions. Access our comprehensive Test Series, original Mock Tests, and interactive learning modules. Many premium tests are completely free!

  • Original Mocks & Regular Test Series
  • Real NTA-like Interface with Analytics
  • Many Free Tests Available