The frictional force acting on $1 \mathrm{kg}$ block is

If acceleration of $A$ is $2 \mathrm{m}\hspace{0.17em}{\mathrm{s}}^{-2}$ which is smaller than acceleration of $B$ then the value of frictional force applied by $B$ on $A$ is

Acceleration of block $A$ Varies with time as shown in figure the value of coefficient of kinetic friction between block $A$ and $B$ is

Blocks shown in figure moves with constant velocity $10 \mathrm{m}\hspace{0.17em}{\mathrm{s}}^{-1}$ Towards right. All surfaces in contact are rough. The friction force applied by $B$ on $A$ is

A block of weight $W$ is supported by three strings as shown in figure. Which of the following relations is true for tension in the strings? (Here $T_1,T_2$ and $T_3$ are the tension in the strings $A, B$ and $C$ respectively)