Question

Two concentric shells have masses $M$ and $m$ and their radii are $R$ and $r$, respectively, where $R>r$.

What is the gravitational intensity at a point for which $x<r$?

• A. $\frac{GM}{r^2}$
• B. $\frac{GM}{x^2}$
• C. $\frac{GM}{R^2}$
• D. $Zero$

Answer 1

The correct option is D $Zero$

For region where $x<r$, the net mass density is zero so there is nothing to attract the other bodies and thus there will not be any gravitational intensity for $x<r.$

It is similar like that of electric field. When net charge enclosed in the Gaussian sphere is zero, then there is no electric field.