In the figure shown $'P'$ is a plate on which a wedge $B$ is placed and on $B$ a block $A$ of mass $m$ is placed. The plate is suddenly removed and system of $B$ and $A$ is allowed to fall under gravity. Neglecting any force due to air on $A$ and $B$, the normal force on $A$ due to $B$ is

A book of mass $5 \,kg$ is placed on a table and it is pressed by $10 \,N$ force then normal force exerted by the table on the book is ......... $N$

Three solids of masses ${m_1},\,{m_2}$ and ${m_3}$ are connected with weightless string in succession and are placed on a frictionless table. If the mass ${m_3}$ is dragged with a force T, the tension in the string between ${m_2}$ and ${m_3}$ is

Two blocks of mass $M_1 = 20\,kg$ and $M_2 = 12\,kg$ are connected by a metal rod of mass $8\,kg.$ The system is pulled vertically up by applying a force of $480\,N$ as shown. The tension at the mid-point of the rod is ........ $N$

$T_1$ and $T_2$ in the given figure are

What force should be applied on the wedge so that block over it does not move? (All surfaces are smooth)