When electric bulbs of same power, but different marked voltage are connected in series across the power line, their brightness will be :
Medium
Download our app for free and get started
Resistance of bulb $R=\frac{V^{2}}{P}$, Where $V$ is the marked voltage and $P$ is the marked power $P$. is same for both As both bulbs are connceted in series, so current in both of them will be same. So Brightness $\propto R \propto V^{2}$
Download our appand 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.*
Similar Questions
- 1A wire of resistance $160\,\Omega$ is melted and drawn in wire of one-fourth of its length. The new resistance of the wire will be $......\Omega$View Solution
- 2Two long coaxial and conducting cylinders of radius $a$ and $b$ are separated by a material of conductivity $\sigma$ and a constant potential difference $V$ is maintained between them, by a battery. Then the current, per unit length of the cylinder flowing from one cylinder to the other is -View Solution
- 3It is preferable to measure the $e.m.f.$ of a cell by potentiometer than by a voltmeter because of the following possible reasons.View Solution
$(i)$ In case of potentiometer, no current flows through the cell.
$(ii)$ The length of the potentiometer allows greater precision.
$(iii)$ Measurement by the potentiometer is quicker.
$(iv)$ The sensitivity of the galvanometer, when using a potentiometer is not relevant.
Which of these reasons are correct? - 4The length of a potentiometer wire is $l$. $A$ cell of $\mathrm{emf}$ $E$ is balanced at a length $l/3$ from the positive end of the wire. If the length of the wire is increased by $l/2$. At what distance will the same cell give a balance point.View Solution
- 5If the galvanometer $G$ does not show any deflection in the circuit shown, the value of $R$ is given by $............\Omega$View Solution
- 6In the given figure, battery $E $ is balanced on $55\, cm$ length of potentiometer wire but when a resistance of $10 \,\Omega$ is connected in parallel with the battery then it balances on $50\, cm$ length of the potentiometer wire then internal resistance $r$ of the battery is ............. $\Omega $View Solution
- 7A car has a fresh battery of $e.m.f$. $12\, V$ and internal resistance of $0.05\, \Omega$. If the starter motor draws a current of $90\, A$, the terminal voltage when the starter is on will be ............... $V$View Solution
- 8On an electric heater $220\, volt$ and $1100\, watt$ are marked. On using it for $4$ hours, the energy consumed in $kWh$ will beView Solution
- 9$n$ identical cells are joined in series with its two cells $A$ and $B$ in the loop with reversed polarities. $EMF$ of each shell is $E$ and internal resistance $r$. Potential difference across cell $A$ or $B$ is (here $n > 4$)View Solution
- 10Five cells each of emf $E$ and internal resistance $r$ are connected in series. Due to oversight one cell is connected wrongly. The equivalent internal resistance of the combination is ........... $r$View Solution