Question

if you hold a plastic comb in your hand and rub it in your hair. However if you do the same with a metal comb.

Answer 1

It happens with plastic comb due to static friction but it will not happen with metal comb.

Answer 2

Both plastic and metal comb will get charged when rubbed in the hair. However, since metal is a conductor, the charges will flow to earth through the body and it will lose its charge. If the metal comb has an insulating plastic handle it will retain its charge.