Power dissipated across the 8  Ω resistor in the circuit shown here is 2 W. The power dissipated in watt units across the 3  Ω resistor is

Resistances 1  Ω and 3  Ω are connected in series, so effective resistanceR'=1+3=4  ΩNow, R' and 8  Ω are in parallel. We know that potential difference across resistances in parallel order is the same.Hence, R'×  i1=8i2 or   4  ×   i1  =  8i2   or  i1 = 84  i2  =  2i2or  i1 = 2i2                           …..(i)Power dissipated across 8  Ω resistance is           i22  8t=2  Wor            i22 t=28=0.25  W           ….(ii)Power dissipated across 3  Ω resistance is H=i12  3t=2i22  3t=12i22 tBut    i22 t=0.25  WH=12  ×  0.25  =  3  W