Question

Which one of the following graphs represents correctly the variation of gravitational field intensity (I) with the distance (r) from the center of a spherical shell of uniform mass 'M' and radius 'a'

• A. A
• B. B
• C. C
• D. D

Answer 1

Answer: (B)

B

Answer 2

The gravitational field intensity inside a uniform spherical shell ($r < a$) is zero. Outside the shell ($r > a$), the field intensity is given by $I = \frac{GM}{r^2}$, where $M$ is the mass of the shell, $G$ is the gravitational constant, and $r$ is the distance from the center. At the surface of the shell ($r = a$), the field intensity is $I = \frac{GM}{a^2}$. Graph B correctly represents this variation by showing zero intensity for $r < a$, a peak value at $r = a$, and a $1/r^2$ decay for $r > a$.