A potentiometer circuit shown in the figure is set up to measure $e.m.f.$ of a cell $E$. As the point $P$ moves from $X$ to $Y$ the galvanometer $G$ shows deflection always in one direction, but the deflection decreases continuously until $Y$ is reached. In order to obtain balance point between $X$ and $Y$ it is necessary to
ADecreases the resistance $R$
BIncrease the resistance $R$
CReverse the terminals of battery $V$
DReverse the terminals of cell $E$
Easy
Download our app for free and get started
ADecreases the resistance $R$
a (a) Decreasing $R$ increases current in $XY$ and there by increases the potential drop across $XP$ and the balance point may be obtained. The current may be increased also by increasing $V.$
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.*
At room temperature, copper has free electron density of $8.4 \times {10^{28}}$ per ${m^3}$. The copper conductor has a cross-section of $10^{-6} \,m^2$ and carries a current of $5.4\, A$. The electron drift velocity in copper is
If resistivity of all four wire connected in parallel is different as given in figure and all other dimensions of wire are same then current $i$ is (resistance of wire having resistivity $\rho $ is $R_0$ )
Three resistors each of $4\,\Omega $ are connected together to form a network. The equivalent resistance of the network cannot be ............ $\Omega$
Two electric bulbs rated ${P_1}\,watt$ $V\, volts$ and ${P_2}\, watt$ $V\, volts$ are connected in parallel and $V\, volts$ are applied to it. The total power will be
A cell can be balanced against $110\,\, cm$ and $100\,\, cm$ of potentiometer wire, respectively with and without being short circuited through a resistance of $10 \,\,\Omega$. Its internal resistance is ............... $\Omega$
In a building there are $15$ bulbs of $45\; \mathrm{W}, 15$ bulbs of $100\; \mathrm{W}, 15$ small fans of $10 \;\mathrm{W}$ and $2$ heaters of $1 \;\mathrm{kW}$. The voltage of electric main is $220\; \mathrm{V}$. The minimum fuse capacity (rated value) of the building will be: .......... $A$
A current of $6\, A$ enters one corner $P$ of an equilateral triangle $PQR$ having $3$ wires of resistance $2 \,\Omega$ each and leaves by the corner $R$. The currents $i_{1}$ in ampere is ........ .