We know that the gravitational field strength is zero insdie a spereical shell of matter. The electrical field strenght is zero not only insdie an isolated charged spherical conductor but inside an isolated cunductor of any shap . Is the gravitational field strength inside, say, a cubical shell of matter zer? if not, in what respect is the analogy not complete?

Explanation

To solve the question, we need to analyze the gravitational field strength inside a cubical shell of matter and compare it to the electric field inside a conductor.

### Step-by-Step Solution:

1. **Understanding Gravitational Field Inside a Spherical Shell:**
- It is known that the gravitational field strength inside a spherical shell of uniform mass distribution is zero. This is due to the symmetry of the shell, where the gravitational forces from different parts of the shell cancel each other out at any point inside the shell.

2. **Considering a Cubical Shell:**
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