38) Which of the following abrasive materials would be used to clean the steel before brazing ?

Wet and dry silicon carbide paper

Emery cloth

Wire wool

Aluminium oxide paper

Answer is:

Emery cloth

Explanation:

Emery cloth is used as abrasive materials to clean the steel before brazing.

To prevent steel from oxidizing during brazing process

To speed up brazing process

To clean the metal by dissolving any oxide already present

To make the final joint clean

Answer is:

Explanation:

Flux is used in brazing to clean the metal by dissolving any oxide already present.

slowly

rapidly

under cold water

at any rate

Answer is:

Explanation:

When brazing is completed workpiece should be cooled slowly.

Viscosity

Density

Melting point

Capillarity

Answer is:

Brass to brass

Copper to copper

Steel to steel

Aluminium to aluminium

Answer is: