question_answer

Two concentric uniform shells of mass \[{{M}_{1}}\] and \[{{M}_{2}}\] are as shown in the figure. A particle of mass m is located just within the shell \[{{M}_{2}}\] on its inner surface. Gravitational force on 'm' due to \[{{M}_{1}}\] and \[{{M}_{2}}\] will be

A) Zero     

B) \[\frac{G{{M}_{1}}m}{{{b}^{2}}}\]

C)   \[\frac{G\left( {{M}_{1}}+{{M}_{2}} \right)m}{{{b}^{2}}}\]

D) None of these