99 Percentile Qs Bank for JEE MainPhysicsCurrent Electricity
A 25 W , 220 V bulb and 100 W , 220 V bulb are joined in series and connected to the mains. Which bulb will glow brighter -
Options
- A25 W bulb
- B100 W bulb
- CFirst 25 W bulb and then 100 W bulb
- DBoth will glow with same brightness
Correct answer
A. 25 W bulb
Step-by-step solution
(Brightness) ∝ (Consumed power) .....(i) For series combination P c o n s u m e d = i 2 R ∴ P c o n s u m e d ∝ R ......(ii) Also, Rated Power P R a t e d = V 2 R P R a t e d ∝ 1 R .....(iii From, (i), (ii) and (iii) B r i g h t n e s s ∝ 1 P r a t e d ∴ 25 W bulb will glow brighter.