An electric bulb marked $40\, W$ and $200\, V$, is used in a circuit of supply voltage $100\, V$. Now its power is
AIIMS 2002, Medium
Download our app for free and get started
(d) $P = \frac{{{V^2}}}{R}$ $ \Rightarrow \frac{{{P_2}}}{{{P_1}}} = \frac{{V_2^2}}{{V_1^2}}$ ( is constant)
$ \Rightarrow \frac{{{P_2}}}{{{P_1}}} = {\left( {\frac{{100}}{{200}}} \right)^2} = \frac{1}{4}$$ \Rightarrow {P_2} = \frac{{{P_1}}}{4} = \frac{{40}}{4} = 10\,W$
$ \Rightarrow \frac{{{P_2}}}{{{P_1}}} = {\left( {\frac{{100}}{{200}}} \right)^2} = \frac{1}{4}$$ \Rightarrow {P_2} = \frac{{{P_1}}}{4} = \frac{{40}}{4} = 10\,W$
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 SolutionFollowing figure shows four situations in which positive and negative charges moves horizontally through a region and gives the rate at which each charge moves. Rank the situations according to the effective current through the region greatest first
- 2Three resistors having resistances $\mathrm{r}_{1}, \mathrm{r}_{2}$ and $\mathrm{r}_{3}$ are connected as shown in the given circuit. The ratio $\frac{i_{3}}{i_{1}}$ of currents in terms of resistances used in the circuit is :View Solution
- 3The resistivity $(\rho)$ of semiconductor varies with temperature. Which of the following curve represents the correct behaviourView Solution
- 4The effective resistance of the network between points $A$ and $B$ isView Solution
- 5Assertion : When current through a bulb decreases by $0.5\%$, the glow of bulb decreases by $1\%$.View Solution
Reason : Glow (Power) which is directly proportional to square of current.
- 6In the given circuit, it is observed that the current $I$ is independent of the value of the resistance $R_6$. Then the resistance values must satisfyView Solution
- 7An electric toaster has resistance of $60\ \Omega$ at room temperature $\left(27^{\circ} \mathrm{C}\right)$. The toaster is connected to a $220 \mathrm{~V}$ supply. If the current flowing through it reaches $2.75 \mathrm{~A}$, the temperature attained by toaster is around : (if $\alpha=2 \times 10^{-4} /{ }^{\circ} \mathrm{C}$ )View Solution
- 8Three unequal resistors in parallel are equivalent to a resistance $1\, ohm$. If two of them are in the ratio $1 : 2$ and if no resistance value is fractional, the largest of the three resistances in $ohms$ isView Solution
- 9The heat produced by a $100\, watt$ heater in $2$ minute will be equal toView Solution
- 10The reading of voltmeter is :- .............. $V$View Solution
