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Question #43742
The Question
A p-polarized plane electromagnetic wave is incident from vacuum () onto a non-magnetic dielectric medium with refractive index . The interface at is coated with an ultra-thin metamaterial that acts as a localized displacement current source, providing an effective surface current density , where is the tangential electric field and is a real constant. The incident magnetic field is given by . It is observed that the reflected wave is completely extinguished when the angle of incidence is . Given the impedance of free space is , what is the value of the dimensionless parameter ?
Options
- A.
- B.
- C.
0
- D.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Intuition_Breaker
Train your brain to resist "obvious" answers that are designed to deceive your intuition.
Concepts Behind This Question
Brewster's Law|Wave Equation Sign Convention|Displacement Current Source
Why This Question Is Tricky
Common Mistakes
This question tests the fundamental origin of Brewster's angle by disrupting the standard boundary conditions.
Students typically memorize , which assumes continuity of the tangential magnetic field (Option C trap).
By introducing a localized displacement current (effective surface current) at the boundary, the Ampere-Maxwell law () dictates a jump in the tangential H-field.
Students must re-derive the Fresnel reflection coefficient from first principles, correctly applying the wave equation sign convention to relate E and H fields, and solve the modified boundary value problem to find the new zero-reflection condition.
A sign error in the boundary condition cross product leads to Option B.
Quick Facts About This Question
Question Information
| Subject | Physics |
| Chapter | Wave Optics - Class 12 |
| Concept | Brewster's Law |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |