Which of the following groups of forces could be in equilibrium?

$A$ flexible chain of weight $W$ hangs between two fixed points $A$ and $B$ which are at the same horizontal level. The inclination of the chain with the horizontal at both the points of support is $\theta$. What is the tension of the chain at the mid-point?

The adjoining figure shows a force of $40\, N$ acting at $30^o$ to the horizontal on a body of mass $5\, kg$ resting on a smooth horizontal surface. Assuming that the acceleration due to gravity is $10\, ms^{-2}$,which of the following statements is (are) correct?
$[1]$ The horizontal component of the applied force is $20\sqrt{3}\, N$.
$[2]$ The weight of the $5\, kg$ mass acts vertically downwards.
$[3]$ The net vertical force acting on the body is $30\, N$ (upwards).

An iron sphere weighing $10 \, N$ rests in a $V$-shaped smooth trough whose sides form an angle of $60^o$ as shown in the figure. Then the reaction forces are:

When is a body said to be in mechanical equilibrium?

$A$ mass '$M$' is suspended by a rope from a rigid support at point '$P$' as shown in the figure. Another rope is tied at end '$Q$' and pulled horizontally with a force '$F$'. If the rope makes an angle '$\theta$' with the vertical,then the tension in the string '$PQ$' is