Two concentric shells of masses `M_(1)` and `M_(2)` are having radii `r_(1)` and `r_(2)`. Which of the following is the correct expression for the gravitational field on a mass `m`?

Two concentric shells of masses M_(1) and M_(2) are having radii r_(1) and r_(2) . Which of the following is the correct expression for the gravitational field at a distance r ?

Assertion : Two spherical shells have masses m_(1) and m_(2) . Their radii are r_(1) and r_(2) . Let r be the distance of a point from centre. Then gravitational field strength and gravitational potential both are equal to zero for O lt r lt r_(1) Reason : In the region r_(1) lt r lt r_(2) , gravitational field strength due to m_(2) is zero. But gravitational potential due to m_(2) is constant (but non-zero).

Assertion : Two spherical shells have masses m_(1) and m_(2) . Their radii are r_(1) and r_(2) . Let r be the distance of a point from centre. Then gravitational field strength and gravitational potential both are equal to zero for O lt r lt r_(1) Reason : In the region r_(1) lt r lt r_(2) , gravitational field strength due to m_(2) is zero. But gravitational potential due to m_(2) is constant (but non-zero).

Two concentric spherical shells have masses m_(1) and m_(2) and radii r_(1) and r_(2) (r_(2) gt r_(1)) . What is the force exerted by this system on a particle of mass m_(3) . If it is placed at a distance r(r_(1) lt r lt r_(2)) from the centre ?

Two concentric spherical shells have masses m_(1) and m_(2) and radii r_(1) and r_(2) (r_(2) gt r_(1)) . What is the force exerted by this system on a particle of mass m_(3) . If it is placed at a distance r(r_(1) lt r lt r_(2)) from the centre ?

Consider three concentric shells of masses M_(1),M_(2) and M_(3) having radii a,b and c respectively are situated as shown in Gravitational field at a point located at Q and P is