Question

A particle of mass $M$ is at a distance $a$ from surface of a thin spherical shell of equal mass and having radius $a$. Choose the correct statement .

• A. Gravitational field and potential both are zero at centre of the shell
• B. Gravitational field is zero not only inside the shell but also at a point outside the shell also .
• C. Inside the shell, gravitational field alone is zero
• D. Neither gravitational field nor gravitational potential is zero inside the shell (except at center)

Answer 1

The correct option is D Neither gravitational field nor gravitational potential is zero inside the shell (except at center)

At a point inside the shell, the field due to the shell is zero while due to the particle is non zero.

At a point inside the shell, potential due to the shell is non zero and negative and due to the particle is also non zero negative. Hence the total potential is not zero .

Why this question: It is absolutely important to be well versed with the field due to a solid sphere and a hollow sphere both inside and outside.