What is the gravitational field at a point inside a spherical shell?

What is the gravitational force on a body inside a spherical shell? Why is it so?

what is gravitational force ?

How the gravitational field at a point inside a solid sphere vary with distance x from its centre, if x R (R-radius)?

What is the gravitational potential at infinity?

Define gravitational potential at a point

what is the range of gravitational force ?

What is the magnetic field at a point placed outside of a long solenoid carrying current I.

What will be the magnetic field at a point on the axis of a long solenoid containing 10 turns per cm length, when a current of 1 ampere flows through it ?