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 r

Question

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 $R_{100}, R_{60}$ and $R_{40}$ , respectively, the relation between these resistances is

Options:

Answer:

D

Solution:

$R = \frac{V ^{2}}{P}$ or $R \propto \frac{1}{P}$ $∴ \frac{1}{R _{100}} > \frac{1}{R _{60}} > \frac{1}{R _{40}}$ Hence, the correct option is (d).

TestHub · Accepted Answer

R = P V 2 ​ or R ∝ P 1 ​ ∴ R 100 ​ 1 ​ > R 60 ​ 1 ​ > R 40 ​ 1 ​ Hence, the correct option is (d).

Physics - Current Electricity Question with Solution | TestHub

Options:

Doubts & Discussion