JEE Main 26-Aug-2021 Shift 1 Solved Paper

The uniform spherical shell is shown in the figure below Inside the shell, there is no mass, so by applying Gauss’s law forgravitation
∮g.da=−4πGMenclosed
where, g = gravitational field intensity.
da = area enclosed
G = gravitational constant
and Menclosed= mass enclosed .
As, Menclosed=0
So, gravitational field intensity is zero inside the shell, i.e. g = 0 …(i)
We also know that,
g=−

dV

dr

where, dV is change in potential due to gravity
⇒ V = constant [using Eq. (i)]
So, gravitational field is zero everywhere inside the shell and
gravitational potential (V) is constant everywhere.