If two bulbs of `25 W and 100 W` rated at `220 V` are connected in series across a `440 V` supply, will both the bulbs fuse ? If not which one ?

Options

A. 100W bulb will fuse
B. 25W bulb will fuse
C. none will free
D. both will fuse

Answer

B

Explanation

`R_(1) = ((220)^(2))/(25) = 4R, R_(2)= ((220)^(2))/(25) = R`

`V_(1) = (4R)/(4R+R) xx 440 = 352 V`
`V_(2) = 440-352 = 88V`
Voltage across first bulb gt rated voltage `I^(st)` bulb will fuse.