$A$ brass disc and a carbon disc of same radius are assembled alternatively to make a cylindrical conductor. The resistance of the cylinder is independent of the temperature. The ratio of thickness of the brass disc to that of the carbon disc is [$\alpha$ is temperature coefficient of resistance and Neglect linear expansion ]
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.*
In a potentiometer (see figure) a balance is obtained at a length of $400\ mm$ when using a known battery of emf $1.6\ V$. After removing this battery, another battery of unknown emf is used and balance is obtained at a length of $650\ mm.$ The emf of unknown battery is ............. $volt$
In the network shown in the figure, each of the resistance is equal to $2\,\Omega $. The resistance between the points $A$ and $B$ is .............. $\Omega$
Every atom makes one free electron in copper. If $1.1$ $ampere$ current is flowing in the wire of copper having $1\, mm$ diameter, then the drift velocity (approx.) will be (Density of copper $ = 9 \times {10^3}\,kg\,{m^{ - 3}}$ and atomic weight = $63$)
The length of a potentiometer wire is $l$. $A$ cell of $\mathrm{emf}$ $E$ is balanced at a length $l/3$ from the positive end of the wire. If the length of the wire is increased by $l/2$. At what distance will the same cell give a balance point.
There are a large number of cells available, each marked $(6 \,V , 0.5 \,\Omega)$ to be used to supply current to a device of resistance $0.75 \,\Omega$, requiring $24 \,A$ current. How should the cells be arranged, so that power is transmitted to the load using minimum number of cells?