A spherical conducting shell of inner radius `r_(1)` and outer radius `r_(2)` has a charge Q.
(a) A charge q is placed at the center of the shell. What is the surface charge density on the inner and outer surfaces of the shell ?
(b) Is the electric field intensity inside a cavity (with no charge) zero, even if the shell is not spherical, but has any irregular shape ? Explain.

Explanation

To solve the problem step by step, we will address both parts of the question regarding the spherical conducting shell.

### Part (a): Surface Charge Density on the Inner and Outer Surfaces

1. **Understanding the Setup**:
- We have a spherical conducting shell with inner radius \( r_1 \) and outer radius \( r_2 \).
- The shell has a total charge \( Q \).
- A charge \( q \) is placed at the center of the shell.
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