A voltmeter is connected in parallel with a variable resistance $R$ which is in series with an ammeter and a cell as shown in the figure. For one value of $R$, the meters read $0.3 \,A$ and $0.9 \,V$. For another value of $R$ the readings are $0.25 \,A$ and $1.0 \,V$. What is the internal resistance of the cell is ......... $\Omega$
A$0.5$
B$2$
C$1.2$
D$1$
Easy
Download our app for free and get started
B$2$
b (b)
$^-0.9=^-E-^+0.3 r$
$1=E-0.25 r$
$0.1=0.05 r$
$r=\frac{10}{5}=2 r$
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.*
The balancing length for a cell is $560 \;\mathrm{cm}$ in a potentiometer experiment. When an external resistance of $10 \;\Omega$ is connected in parallel to the cell, the balancing length changes by $60\; \mathrm{cm} .$ If the internal resistance of the cell is $\frac{\mathrm{N}}{10} \;\Omega,$ where $\mathrm{N}$ is an integer then value of $\mathrm{N}$ is
A source of $e.m.f.$ $E = 15\,V$ and having negligible internal resistance is connected to a variable resistance so that the current in the circuit increases with time as $i = 1.2 t + 3$. Then, the total charge that will flow in first five second will be ............... $C$
For the circuit shown, with ${R_1} = 1.0\,\Omega $, ${R_2} = 2.0\,\Omega $, ${E_1} = 2\,V$ and ${E_2} = {E_3} = 4\,V$, the potential difference between the points $‘a’$ and $‘b’$ is approximately (in $V$)
For a wire $\frac{R}{l}=\frac{1}{2}$ and length of wire is $l=5\, cm .$ If potential difference $1\, V$ is applied across it, current through wire will be: $( R =$ Resistance $)$ (in $A$)
In the given circuit, an ideal voltmeter connected across the $10\,\Omega $ resistance reads $2\, V$. The internal resistance $r$, of each cell is ................... $\Omega$
A wire is connected to a battery between the point $M$ and $N$ as shown in the figure $(1)$. The same wire is bent in the form of a square and then connected to the battery between the points $M$ and $N$ as shown in the figure $(2)$. Which of the following quantities increases?
Four equal resistance dissipated $5 \,W$ of power together when connected in series to a battery of negligible internal resistance. The total power dissipated in these resistance when connected in parallel across the same battery would be ........... $W$