For the post office box arrangement to determine the value of unknown resistance the unknown resistance should be connected between
IIT 2004, Medium
Download our app for free and get started
(c) Post office box is based on the principle of Wheatstone's bridge
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.*
A potentiometer wire of length $L$ and a resistance $r$ are connected in series with a battery of e.m.f. $E_0$ and a resistance $r_1$. An unknown e.m.f. $E$ is balanced at a length $l$ of the potentiometer wire. The e.m.f. $E$ will be given by
Two electric bulbs whose resistances are in the ratio of $1 : 2$ are connected in parallel to a constant voltage source. The powers dissipated in them have the ratio
An ammeter $A$ of finite resistance, and a resistor $R$ are joined in series to an ideal cell $C$. $A$ potentiometer $P$ is joined in parallel to $R$. The ammeter reading is $I_0$ and the potentiometer reading is $V_0$. $P$ is now replaced by a voltmeter of finite resistance. The ammeter reading now is $I$ and the voltmeter reading is $V$.
To get maximum current through a resistance of $2.5\,\Omega $, one can use $m$ rows of cells, each row having $n$ cells. The internal resistance of each cell is $0.5\,\Omega $. What are the values of $n$ and $m$ if the total number of cells is $45$ ?
In the circuit shown, current through $R_2$ is zero. If $R_4 = 2\,\Omega $ and $R_3 = 4\,\Omega $ , current through $R_3$ will be ................. $\mathrm{A}$
In a potentiometer experiment shown here, for the position $X$ of the jockey $J,$ there occurs a null deflection in the galvanometer. Then the potential difference between points $A$ and $X$ is ................ $V$