Production & Engineering Materials - 1 - Mechanical Engineering MCQ

Oxyacetylene reducing flame is used while carrying out the welding on

The purpose of chaplets is

Match List - I (Name of the Element) with List - II (Crystal Structure) and select the correct answer using the codes given below the lists:

L ist - I
P. Fluorspar
Q. Alpha-Iron
R. Silver
S. Zinc

List - II
1. Body-centered cubic
2. Hexagonal close packed
3. Simple cubic
4. Face-centered cubic

Welding of C40 steel plate of 10 mm thickness required a current of 150 amps, while it was 350 amps when the plate thickness was increased by 50%. Estimate the welding current for 8.25 mm thickness of same material.

In gas welding of mild steel using an oxy-acetylene consumed was 10 liters. The oxygen consumption from the cylinder is

A spot welding obtained with a current of 40000 A for a period of 0.01 sec. If the effective resistance of the joint be taken as 120 micro ohms, and if the joint can be considered as a cylinder of 6mm diameter and 3 mm in height, the heat distributed to the surroundings is ________ J. (Take heat re q u ired for m eltin g steel as 10 J/mm³) 

A slot 25 mm deep is to be cut through a workpiece 200 mm long with the help of HSS side and face cutter whose diameter is 150 mm and has 10 teeth. If cutting speed is 50 m/min and feed is 0.25 mm per teeth, then time (in sec) required to machine the slot is