Question

Two electric bulbs have tungsten filament of same length. If one of them gives `60 W` and the other `100 W` , then
A. `100 W` bulb has thicker filament
B. `60 W` bulb has thicker filament
C. both filaments are of same thickness
D. it is not possible to get different wattages unless the lengths are different

Answer 1

Correct Answer - A
`P = V^(2)//R` . If `P` is more , `R` is less . `R = rho l // a`. For less `R`, a is more . So the `100 W` bulb has thicker element .