Three identical bulbs connected in series across an accumulator consumes 20 W power. If the bulbs are connected in parallel to the same source, the power consumed is

Options

A. 20 W
B. 60 W
C. 90 W
D. 180 W

Answer

D

Explanation

If N bulbs are identical, then in series the total power
`P_("total")=(P)/(N)`
`20=(P)/(3)`
`P=60W`
Each bulb has power of 60 W.
In parallel combination,
`P=P_(1)+P_(2)+P_(3)`
`=60+60+60`
`=180W`