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Question #43363
The Question
A solid conductor is shaped as a spherical sector (a truncated cone bounded by two spherical caps centered at the apex). The inner spherical cap has a radius and the outer spherical cap has a radius . The solid angle subtended by the sector at the apex is . The conductor is made of a non-Ohmic material where the local electric field magnitude and current density magnitude are related by , where is a positive constant. A steady current flows radially outward from the inner cap to the outer cap. The conductor is conceptually divided into two segments by an intermediate spherical cap of radius . What is the ratio of the total power dissipated in the inner segment () to that in the outer segment ()?
Options
- A.
- B.
3
- C.
- 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
Power Dissipation Ratio|Potential Gradient Direction|Vector Cross-Product
Why This Question Is Tricky
Common Mistakes
This question tests the fundamental field-theoretic definition of power dissipation in a non-uniform, non-Ohmic geometry.
The 'Lethal Collision' occurs when students blindly apply Ohmic formulas (yielding a ratio of 3) or assume a constant current density (yielding a ratio of 7/19 based purely on volume).
By forcing the current density lines to diverge radially in a non-Ohmic medium (), the local power density becomes proportional to , requiring students to abandon 1D circuit approximations and correctly integrate the spatially varying fields.
Quick Facts About This Question
Question Information
| Subject | Physics |
| Chapter | Current Electricity - Class 12 |
| Concept | Power Dissipation Ratio |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |