27) The material used in furnace wall as a inner most layer, to resist high temperatures, physical and chemical reactions is called

Answer is:

Refractory

ISRO Technician-B Fitter Question Paper - 2016 (Set - 2) with Answer Key

28) The forging process in which, the length of forge reduces and cross section increases is called

Answer is:

Upsetting

Explanation:

1)Drawing Down: Drawing down is a process of elongate the length and reduce the cross section area of work piece. Simply in this operation, the length of work piece increases and the cross section area decreases. In this process, a compressive force is applied at perpendicular direction of its length axis. If a tensile force is applied to change its length at parallel to its length axis, this process is known as wire drawing.

2) Upsetting: Upsetting is just opposite operation to drawing down. In this operation, the length of work piece decreases and its cross section area increases. In this process, a compressive force is applied at parallel direction to its length axis.