Question

Two bulbs of 100 w each are connected (I) in series (II) in parallel to 220 volt supply. In which of the cases they will consume less power and why?

Answer 1

Hey mate...

We have,
Power =100w
Voltage =220v

We know that
P=v^2/R
100=220*220/R
R=220*220/100
R=22*22
R=484ohm

Now,
In series

Equavalent resistance =484+484
=968ohm

Now,
In parallel

Equavalent resistance=R1*R2/R1+R2
=242ohm

Since Equavalent resistance is less in parallel connection.
SO in parallel connection less power consume...