A level having $${90^0}$$ bend is to be produced by drop forging using mild steel bar as raw material. The various operations to be performed on it during forging are:
$$P$$ - Cutting;
$$Q$$ - Bending;
$$R$$ - Fullering;
$$S$$ - Blocking cum finishing;
$$T$$ - Edgering

The correct sequence for performing the operations is:

Assertion (A) : Cold working of metals result in increase of strength and hardness.
Reason (R) : Cold working reduces the total number of dislocations per unit volume of the material.

The extrusion process(es) used for the production of toothpaste tubes is / are

$$1.$$ Tube extrusion
$$2.$$ Forward extrusion
$$3.$$ Impact extrusion

Cold working produces the following effects

$$1.$$$$\,\,\,\,\,\,\,\,\,\,\,\,\,\,$$ Stress are set up in the material
$$2.$$$$\,\,\,\,\,\,\,\,\,\,\,\,\,\,$$ Grain structure get distorted
$$3.$$$$\,\,\,\,\,\,\,\,\,\,\,\,\,\,$$ Strength and hardness of the metal are decreased
$$4.$$$$\,\,\,\,\,\,\,\,\,\,\,\,\,\,$$ Surface finish is reduced