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

In an explosive welding process, the ..................... (maximum/minimum) velocity of impact is fixed by the velocity of sound in the ............. (flyer / target) plate material.

For gas welding a particular job using a neutral oxy-acetylene flame the acetylene consumption was $$10$$ ltrs. The oxygen consumption from the cylinder in liters will be

Penetration is increased by