what himanshu told is  correct yaar...........then for the second one i think PANDEY is correct...because if comb got +ve charge means electrons will flow  from earth to it to make it at same potential... here conduction electrons will be of wire yaar... it is conducting na....if it got -ve charge means it got extra electrons... but they r not attached to atoms of insulator or we can say that they are nearly  free... so they flow thru wire to earth.........        is it correct my FRIENDS?..................   please rate me if u think it ts correct yaar......