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.

Consider the following statements:
In comparison to hot working, in cold working,
$$1.$$ Higher forces are required
$$2.$$ No heating is required
$$3.$$ Less ductility is required
$$4.$$ Better surface finish is obtained.

Which of the statements given above are correct?

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