Question

two bulbs have ratings 100V,220V and 60W,220V which one has greater resistance

Answer 1

Answer :  Power =voltage*Current
           Also ,Voltage =Current *Resistance
                Power is denoted by P,Voltage by V ,Current by I and Resistance by R.
                Bulb One:
                   60 =100*I
                or I =60/100 =0.6Amperes
              Hence , Resistance =Voltage /current 
                                             =100/0.6Ohms 
                                             =166.666 Ohms
              Bulb Two:
                      220 =220*I
                    or I =1
               Therefore , Resistance =voltage/current
                                                   =220/1 =220
                                        

Hence , Bulb second has more resistance.

Thank You.
Regards,
Tawseef

Answer 2

Power= Voltage(V)*Current(I)
          =V*I=V²*R
Therefore Let the resistances of the 1st and 2nd bulbs be R' and R" respectively
Dividing the power equation of the first bulb by the second you get:
(V²*R')/(V²*R")=R'/R"=100/60=10/6  //given
therefore the resistance of the first bulb(R') is higher