Question

Which of the bulbs will fuse and Why? ​

Answer 1

For the first bulb

P=V^2/R

25=220×220×1/R

R=48400/25

R=484×4=1936ohm

current required by first bulb=V/R =220/1935

=0.1

For second bulb

P=V^2/R

100=220×220/R

R=484ohm

current required by first bulb =220/484

=10/22=>0.4

total resistance in series =1936+484=>2420

Current in series =440/2420

=22/121=2/11

this current will be in both bulbs

volt in first bulb =2/11 ×1936=2×176=>352.....i)

volt in second bulb=2/11 ×484 =88

from equation first we get that,first bulb will have 352V,but it can tolerate voltage upto 220V only,

so , First bulb will fuse first

Hence option 3) is correct