2 Easy DC Circuit questions?

[DhanishSemar]

1) The power output of two identical bulbs in parallel is compared to two in series. What is the ratio? Explain what causes the difference.

2) A power pack can produce 10A when two bulbs are connected in parallel. When a third bulb is added it produces 14A. Why?

 

[FazaldinA]

Let
Voltage = V volts
Power of one bulb = W watt
Power of two bulbs = 2W watt
REsistance of one bulb = R = V^2/W ohms
Resistance of Two bulbs = 2.V^2/W ohms
Power of bulbs in series = V^2 / [2V^2/W]
= W/2 watt
Ratio : 2W : W/2
OR 4 : 1 ......................... Answer