ELECTRIC DISPLACEMENT
Chapter 2: Chapter 2 · PHYSICS PART-1 · EN medium
From your actual textbook ✓
What does your textbook say about ELECTRIC DISPLACEMENT?
We have introduced the notion of dielectric constant and arrived at Eq. ( . ), without giving the explicit relation between the induced charge density σp and the polarisation P. We take without proof the result that P ˆ σ = P n where ˆn is a unit vector along the outward normal to the surface. Above equation is general, true for any shape of the dielectric. For the slab in Fig. . , P is along ˆn at the right surface and opposite to ˆn at the left surface. Thus at the right surface, induced charge density is positive and at the left surface, it is negative, as guessed already in our qualitative discussion before.
📖 NCERT Class 12 Physics Part 1 · Page 81
Read from the source
Complete lesson
We have introduced the notion of dielectric constant and arrived at Eq. ( . ), without giving the explicit relation between the induced charge density σp and the polarisation P. We take without proof the result that P ˆ σ = P n where ˆn is a unit vector along the outward normal to the surface.
Above equation is general, true for any shape of the dielectric. For the slab in Fig. . , P is along ˆn at the right surface and opposite to ˆn at the left surface.
Thus at the right surface, induced charge density is positive and at the left surface, it is negative, as guessed already in our qualitative discussion before. Putting the equation for electric field in vector form ˆ ˆ σ P n E n or (ε0 E + P) ˆn =σ The quantity ε0 E + P is called the electric displacement and is denoted by D. It is a vector quantity. Thus,
Related topics
Want this shaped for your exam marks?
Get an AI answer grounded in your actual textbook — with the exact page reference.
Ask AI about this topic →