Incandescent bulbs are designed by keeping in mind that the...

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 \mathrm{~W}, 60 \mathrm{~W}

and

40 \mathrm{~W}

bulbs have filament resistances

R_{100}, R_{60}

and

R_{40}

, respectively, the relation between these resistances is

Options

A $\frac{1}{R_{100}}=\frac{1}{R_{40}}+\frac{1}{R_{60}}$
B $R_{100}=R_{40}+R_{60}$
C $R_{100}>R_{60}>R_{40}$
D $\frac{1}{R_{100}}>\frac{1}{R_{60}}>\frac{1}{R_{40}}$

Correct answer

D. $\frac{1}{R_{100}}>\frac{1}{R_{60}}>\frac{1}{R_{40}}$

Step-by-step solution

R=\frac{V^2}{P}

R \propto \frac{1}{P}

\therefore \quad \frac{1}{R_{100}}>\frac{1}{R_{60}}>\frac{1}{R_{40}}

Hence, the correct option is (d).

Practice Current Electricity on Quantrex Academy →

More from Current Electricity

A metal wire of cross-sectional area 0.5 mm ^2 and length 100 m is connected across a… JEE Advanced 2026 As shown in the figure, the resistance of a galvanometer G can be found by the… JEE Advanced 2026 The stored charge in the capacitor in steady state of the following circuit is ________ μ… JEE Main 2026 A moving coil of galvanometer when shunted with 2\,Ω resistance gives a full scale… JEE Main 2026 Two cells of emfs 1 V and 2 V and internal resistance 2\,Ω and 1\,Ω , respectively… JEE Main 2026 Refer to the circuit diagram given below. The heat generated across the 6\,Ω resistance… JEE Main 2026 In an experiment to determine the resistance of a given wire using Ohm's law, the… JEE Main 2026 Under steady state condition the potential difference across the capacitor in the circuit… JEE Main 2026 Full Current Electricity list All JEE Advanced PYQs