If two electric bulbs have $40\, W$ and $60\, W$ rating at $220\, V$, then the ratio of their resistances will be
Easy
Download our app for free and get started
(d) ${P_{Rated}} \propto \frac{1}{R}$ $ \Rightarrow $ $\frac{{{R_1}}}{{{R_2}}} = \frac{{{P_2}}}{{{P_1}}} = \frac{{60}}{{40}} = \frac{3}{2}$
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
- 1View SolutionA piece of wire is cut into four equal parts and the pieces are bundled together side by side to form a thicker wire. Compared with that of the original wire, the resistance of the bundle is ..........
- 2A circuit of resistacne $R$ is connected to $n$ similar cells. If the current in the circuit is the same when the cells are connected in series or in parallel. If the internal resistacne $r$ of each cell thenView Solution
- 3A parallel combination of two resistors, of $1 \,\Omega$ each, is connected in series with a $1.5 \,\Omega$ resistor. The total combination is connected across a $10\, V$ battery. The current flowing in the circuit is .............. $A$View Solution
- 4A filament bulb $(500 \,W,\,\, 100 \,V)$ is to be used in a $230\, V$ main supply. When a resistance $R$ is connected in series, it works perfectly and the bulb consumes $500\,W.$ The value of $R$ is .................. $\Omega$View Solution
- 5Two batteries $A$ and $B$ each of $e.m.f.$ $2\, V$ are connected in series to an external resistance $R = 1 \,ohm$. If the internal resistance of battery $A$ is $1.9\, ohms$ and that of $B$ is $0.9\, ohm$, what is the potential difference between the terminals of battery $A$ ............. $V$View Solution
- 6A uniform wire of resistance $R$ is uniformly compressed along its length, until its radius becomes $n$ times the original radius. Now resistance of the wire becomesView Solution
- 7Resistance across $A B$ as shown in figure is ............. $\Omega$View Solution
- 8A cell having an emf $\varepsilon$ and internal resistance $r$ is connected across a variable external resistance $R.$ As the resistance $R$ is increased, the plot of potential difference $V$ across $R$ is given byView Solution
- 9To measure the internal resistance of a battery, potentiometer is used. For $\mathrm{R}=10 \Omega$, the balance point is observed at $\ell=500 \mathrm{~cm}$ and for $\mathrm{R}=1 \Omega$ the balance point is observed at $\ell=400 \mathrm{~cm}$. The internal resistance of the battery is approximately :View Solution
- 10View SolutionFind the ratio of currents as measured by ammeter in two cases when the key is open and when the key is closed
