Look at the following question. It is given that the bulbs are in series. Should we use P=(V*V)/R or P=(I*I)R ? Also, as it is given that bulbs are in series ,should current be constant across bulbs voltage vary? If yes,How to obtain the answer using P=I*I*R? (As both equations will give completely opposite answers) please no link, just think about it ,there is nothing worth linking in this question its direct concept clearing question. Thank you
Q.85. Three bulbs of 40 W, 60 W and 100 W are arranged in series with 220 V, which bulb has minimum resistance?
(a) 100 W
(b) 40 W
(c) 60 W
(d) equal in all bulbs
Dear Student ,
Look in this type of cases you must remember you should use little bit of common sense .
Look the bulbs will be in series so the same current will flow through all the bulbs .Therefore the bulb with low wattage will have the highest resistance , and the bulb with highest wattage will have lowest resistance among the bulbs .
So hence the 100 W bulb will have minimum resistance .
Regards
Look in this type of cases you must remember you should use little bit of common sense .
Look the bulbs will be in series so the same current will flow through all the bulbs .Therefore the bulb with low wattage will have the highest resistance , and the bulb with highest wattage will have lowest resistance among the bulbs .
So hence the 100 W bulb will have minimum resistance .
Regards