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 $\mathrm{R}_{100}, \mathrm{R}_{60}$ and $\mathrm{R}_{40}$, respectively, the relation between these resistances is
IIT 2010, Medium
Download our app for free and get started
Power $\propto 1 / \mathrm{R}$
Download our app
and get started for free
Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*
When a resistance of $2\, ohm$ is connected across the terminals of a cell, the current is $0.5\, A$. When the resistance is increased to $5\, ohm$, the current is $0.25\, A$. The $e.m.f.$ of the cell is ................. $V$
Carbon resistor has resistance specified by three bands having colour red, yellow and black. If this resistor is cut into two pieces of equal length then the new colour code of each one will be (Neglect tolerance of $4^{th}$ band)
Refer to the circuit shown. What will be the total power dissipation in the circuit if $P$ is the power dissipated in $R_1$ ? It is given that $R_2=4 R_1$ and $R_3=12 R_1$ are .......... $P$
An electric kettle has two heating coils. When one coil is used, water in the kettle boils in $5$ minutes, while when second coil is used, same water boils in $10\,\min$. If the two coils, connected in parallel are used simultaneously, the same water will boil in time
A steady current $I$ is set up in a wire whose cross-sectional area decreases in the direction of the flow of the current. Then, as we examine the narrowing region,