• # question_answer The electric bulbs have tungsten filaments of same length. If one of them gives 60 watt and other 100 watt, then [NCERT 1979] A)            100 watt bulb has thicker filament B)            60 watt bulb has thicker filament C)            Both filaments are of same thickness D)            It is possible to get different wattage unless the lengths are different

${{P}_{Rated}}\propto \frac{1}{R}$and $R\propto \frac{1}{{{\text{(Thickness }\text{of}\,\text{filament)}}^{\text{2}}}}$            So ${{P}_{Rated}}\propto {{(\text{Thickness}\,\text{of}\,\text{filament)}}^{\text{2}}}$