As shown in the figure, a point charge is placed at the centre of a conducting spherical shell of inner radius and outer radius . The electric field due to charge in three different regions I, II, and III is given by: (I : , II : , III : )

- A
- B
- C
- D
As shown in the figure, a point charge is placed at the centre of a conducting spherical shell of inner radius and outer radius . The electric field due to charge in three different regions I, II, and III is given by: (I : , II : , III : )

Correct answer:D
Standard Method
Given: A point charge is placed at the centre of a conducting spherical shell with inner radius and outer radius . The three regions are I : , II : , and III : .
Find: The electric field in the three regions.
From the solution, the working states that the electric field inside the material of a conductor is zero. Therefore, in region II,
Since the point charge is at the centre of the cavity, the field in region I is non-zero due to the enclosed charge:
For points outside the shell, the net enclosed charge is , so the external field is also non-zero:
Thus the physically correct conclusion from the solution is
However, this does not match any listed option verbatim. The solution says The Correct Option is D, but the displayed statement corresponds to neither option D nor the answer key. Therefore the source has an answer-key discrepancy.
Therefore, the correct field pattern is , and the option mapping is ambiguous because no option matches this exactly.
Assuming the electric field is zero everywhere because the shell is a conductor is incorrect. The field is zero only inside the conducting material, not inside the cavity or necessarily outside the shell.
Treating region I as part of the conductor is wrong. Region I is the empty cavity containing the charge , so the field there is non-zero.
Assuming the field outside the shell must vanish is incorrect for an isolated shell with a central charge. Outside, the enclosed net charge is , so the field remains non-zero.
Get unlimited AI-adaptive practice, mastery tracking, and an AI tutor that explains every step — free to start.