A technician has only two resistance coils. By using them singly, in series or in parallel, he is able to obtain the resistance $3,4,12$ and $16 \,ohms$. The resistance of the two coils are ........... $ohms$
Medium
Download our app for free and get started
(b)
$\frac{R_1 R_2}{R_1+R_2}=3$
$R_1+R_2=16$
$R_1 R_2=48$
$R_1\left(16-R_1\right)=48$
$R_1^2-16 R_1+48=0$
$R_1=4,12$
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
- 1Water boils in an electric kettle in $15\,\min$ after switching on. If the length of the heating wire is decreased to $2/3$ of its initial value, then the same amount of water will boil with the same supply voltage in ............. $min$View Solution
- 2If the ammeter in the given circuit reads $2\, A$, the resistance $R$ is ............ $ohm$View Solution
- 3In the given figure, a battery of emf $E$ is connnected across a conductor $P Q$ of length $'Y'$ and different area of cross-sections having radii $r_{1}$ and $r_{2}\left(r_{2}\,<\,r_{1}\right)$.View Solution
Choose the correct option as one moves from $P$ to $Q$ :
- 4A student measures the terminal potential difference $(V)$ of a cell $($ of $emf \;\varepsilon $ and internal resistance $r)$ as a function of the current $(I)$ flowing through it. The slope, and intercept, of the graph between $V$ and $I$, then, respectively, equalView Solution
- 5Resistance of the wire is measured as $2\,\Omega$ and $3\,\Omega$ at $10^{\circ}C$ and $30^{\circ}C$ respectively. Temperature cocoefficient of resistance of the material of the wire is............$^{\circ}C ^{-1}$View Solution
- 6A potentiometer wire $PQ$ of $1\,m$ length is connected to a standard cell $E _{1}$. Another cell $E _{2}$ of emf $1.02\, V$ is connected with a resistance $'r'$ and switch $S$ (as shown in figure). With switch $S$ open, the null position is obtained at a distance of $49\, cm$ from $Q$. The potential gradient in the potentiometer wire is.......$V/cm$View Solution
- 7A silver and zinc voltameter are connected in series and a current $i$ is passed through them for a time $t$ liberating $W\, gm$ of zinc. The weight of silver deposited is nearly ..............$W$View Solution
- 8As shown in the figure, a network of resistors is connected to a battery of $2\,V$ with an internal resistance of $3\,\Omega$. The currents through the resistors $R_4$ and $R_5$ are $I_4$ and $I_5$ respectively. The values of $I_4$ and $I_5$ are :View Solution
- 9A voltmeter of resistance $1000\,\Omega$ is connected across a resistance of $500\, \Omega$ in the given circuit. What will be the reading of voltmeter .............. $V$View Solution
- 10Two wires of equal diameters, of resistivities ${\rho _1}$ and ${\rho _2}$ and lengths $l_1$ and $l_2$, respectively, are joined in series. The equivalent resistivity of the combination isView Solution