Physics, asked by ramrathi, 1 year ago

Which of the following four bulbs when connected in series to a supply of 220v?
a) 40W, 220v
b)80W, 220v
c)100W, 220v
d)60W ,220v

Please also give an explanation to the answer (not just like.. "duhh, 100w has more power therefore itll grow brighter")

Answers

Answered by kvnmurty
5
When all the bulbs are connected in parallel, 100W bulb is brighter. But for series connection, 40W is brighter.

Power is V² / R .
       So for 40W, 220V  bulb:  R = 220² / 40 = 1210 ohms
           for 80W bulb : R = 220² / 80 = 605 ohms
           for 60 W bulb  R =
         for 100 W bulb  R = 484
Let the four bulbs be connected in series with 220V supply. So when bulbs are connected in Series, the bulbs draw same current. ie., power = I² R  being largest the 40 W bulb will glow brighter.  As power dissipated in it is highest.


ramrathi: Thanks alot :D perfect answer
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