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.*
Two wires $A$ and $B$ of the same material, having radii in the ratio $1: 2$ carry currents in the ratio $4: 1$. The ratio of drift speed of electrons in $A$ and $B$ is .......
As shown in the schematic below, a rod of uniform cross-sectional area $A$ and length $l$ is carrying a constant current $i$ through it and voltage across the rod is measured using an ideal voltmeter. The rod is stretched by the application of a force $F$. Which of the following graphs would show the variation in the voltage across the rod as function of the strain $\varepsilon$ when the strain is small. Neglect Joule heating.
In the experiment of $Ohm's law,$ a potential difference of $5.0\, V$ is applied across the end of a conductor of length $10.0\, cm$ and diameter of $5.00\, mm .$ The measured current in the conductor is $2.00\, A$. The maximum permissible percentage error in the resistivity of the conductor is
Five equal resistances each of resistance $R$ are connected as shown in the figure. A battery of $V\, volts$ is connected between $A$ and $B$. The current flowing in $AFCEB$ will be
What length of the wire of specific resistance $48 \times {10^{ - 8}}\,\Omega \,\,m$ is needed to make a resistance of $4.2 \, \Omega$ .............. $m$ (diameter of wire = $0.4\, mm$)
The resistance of platinum wire at $0^{\circ}\,C$ is $2\,\Omega$ and $6.8\,\Omega$ at $80^{\circ} \,C$. The temperature coefficient of resistance of the wire is :
Two batteries one of the $\mathrm{emf}$ $3\,V$, internal resistance $1$ ohm and the other of $\mathrm{emf}$ $15\, V$, internal resistance $2$ $\mathrm{ohm}$ are connected in series with a resistance $R$ as shown. If the potential difference between $a$ and $b$ is zero the resistance of $R$ in $\mathrm{ohm}$ is
$A$ wire of length $L$ and $3$ identical cells of negligible internal resistances are connected in series. Due to the current, the temperature of the wire is raised by $\Delta T$ in time $t. N$ number of similar cells is now connected in series with a wire of the same material and cross section but of length $2L$. The temperature of the wire is raised by the same amount $\Delta T$ in the same time $t$. The value of $N$ is :