two electric bulbs of 50 watt and 100 watt are given. which one will be brighter when they are connected (a)in series (b) in parallel? why?

Asked by  | 21st May, 2013, 07:39: PM

Expert Answer:

1. In series connection - Current across 2 resistors is constant. P = I^2*R
Pconsumed (Brightness) ? V ? R ? 1/Prated i.e. in series combination bulb of lesser wattage will give more bright light. Hence, 50W bulb (220V) will be brighter. 
2. In parallel connection - Voltage drop across the 2 resistors is constant. P = V^2/R
Pconsumed (Brightness) ? PR ? i ? 1/R i.e. in parallel combination, bulb of greater wattage will give more bright light and more current will pass through it. So, 100W bulb will be brighter. 

Answered by  | 22nd May, 2013, 08:09: AM

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