JEE Advanced2010PhysicsCurrent ElectricityActual
Incandescent bulbs are designed by keeping in mind that the resistance of their filament increases with the increase in temperature. If at room temperature, 100 ~W , 60 ~W and 40 ~W bulbs have filament resistances R₁₀₀, R₆₀ and R₄₀ , respectively, the relation between these resistances is
Options
- A1 R₁₀₀ = 1 R₄₀ + 1 R₆₀
- BR₁₀₀=R₄₀+R₆₀
- CR₁₀₀>R₆₀>R₄₀
- D1 R₁₀₀ > 1 R₆₀ > 1 R₄₀
Correct answer
D. 1 R₁₀₀ > 1 R₆₀ > 1 R₄₀
Step-by-step solution
R= V^2 P or R 1 P 1 R₁₀₀ > 1 R₆₀ > 1 R₄₀ Hence, the correct option is (d).