The ratio of acetylene to oxygen is approximately ................ for neutral flame used in gas welding

Generally cylindrical parts produced by powder metallurgy should not have non uniform cross section and a length to diameter ratio exceeding . . . . . . . . . . . . . . .

In $$DC$$ welding, the straight polarity (electrode negative) results in

For resistance spot welding of $$1.5$$ $$mm$$ thick steel sheets, the current required is of the order