Workshop Technology
Riddle is used for

Smoothing and cleaning out depressions in the mould
Moistening the sand around the edge before removing pattern
Cleaning the moulding sand
Reinforcement of sand in the top part of moulding box

ANSWER DOWNLOAD EXAMIANS APP

Workshop Technology
Piercing is an operation of cutting

A hole (other than cylindrical) in a sheet of metal by the punch and the die
A number of holes evenly spaced in a regular pattern on a sheet of metal
A cylindrical hole in a sheet of metal by the punch and the die
A flat sheet to the desired shape

ANSWER DOWNLOAD EXAMIANS APP