If resistance of the filament increases with temperature, what will be power dissipated in a $220\, V- 100\, W$ lamp when connected to $110\, V$ power supply
A$25\, W$
B$< 25\, W$
C$> 25\, W$
D
None of these
Easy
Download our app for free and get started
C$> 25\, W$
c If resistance does not vary with temperature $P_{consumed} = $${\left( {\frac{{{V_A}}}{{{V_R}}}} \right)^2} \times {P_R} = {\left( {\frac{{110}}{{220}}} \right)^2} \times 100 = 25\,W$. But in second cases resistance decreases so consumed power will be more than $25\, W$
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.*
The current in a conductor is expressed as $I=3 t^2+4 t^3$, where $I$ is in Ampere and $t$ is in second. The amount of electric charge that flows through a section of the conductor during $t=1$ s to $t=2 \mathrm{~s}$ is_______ C.
Two identical bulbs are connected in parallel across an ideal source of emf $E$. The ammeter $A$ and voltmeter $V$ are ideal. If bulb $B_2$ gets fused, then
Two cells of $e.m.f.$ $E_1$ and $E_2$ are joined in series and the balancing length of the potentiometer wire is $625$ $cm$. If the terminals of $E_1$ are reversed, the balancing length obtained is $125 \,cm$. Given $E_2 > E_1$, the ratio $E_1: E_2$ will be
In the following circuit composed of identical resistors, across which terminals would you connect a battery in order to dissipate energy in all resistors
$62.5 \times {10^{18}}$ electrons per second are flowing through a wire of area of cross-section $0.1\,{m^2}$, the value of current flowing will be ............ $A$
A square shaped wire with resistance of each side $3\, \Omega$ is bent to form a complete circle. The resistance between two diametrically opposite points of the circle in unit of $\Omega$ will be ......
Four identical electrical lamps are labelled $1.5\,V$, $0.5\,A$ which describes the condition necessary for them to operate at normal brightness. A $12\,V$ battery of negligible internal resistance is connected to lamps as shown, then