Question

How much current will an electric iron draw from a 220 V source if the resistance of its
element when hot is 55 ohms? Calculate the wattage of the electric iron when it operates
on 220 volts.

Answer 1

p.d. = 220 V
R = 55 ohms
So
  
   I,current = V/R
                 = 220/55
              =  4 Ampere

power = v x I
          =  220x4
           =880 Watt

Answer 2

According to ohm's law: V = I R

where  V is voltage applied, in volts(V) 

  I is current drawn, in ampere(A) 

 R is the resistance of the circuit, ohms(Ω)


current = V/R
                 = 220/55
              =  4 Ampere

power = v x I
          =  220x4
           =880 Watt