The temperature coefficient of resistance of tungsten is $4.5 \times 10^{-3}{ }^{\circ} C ^{-1}$ and that of germanium is $-5 \times 10^{-2}{ }^{\circ} C ^{-1}$. A tungsten wire of resistance $100 \,\Omega$ is connected in series with a germanium wire of resistance $R$. The value of $R$ for which the resistance of combination does not change with temperature is .......... $\Omega$
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.*
There are $0.8 \times 10^{23}$ free electrons $/ cm^3$ in copper. If $0.2\, A $ current is flowing is copper wire, then the drift velocity of electrons will be, if the cross sectional area of wire is $0.01 \,cm^2$
In the given potentiometer circuit length of the wire $AB$ is $3\, m$ and resistance is $R = 4.5 \, \Omega$ . The length $AC$ for no deflection in galvanometer is
Six similar bulbs are connected as shown in the figure with a $DC$ source of $emf\; E$, and zero internal resistance. The ratio of power consumption by the bulbs when $(i)$ all are glowing and $(ii)$ in the situation when two from section $A$ and one from section $B$ are glowing, will be
If a $30\, V$, $90\, W$ bulb is to be worked on a $120\, V$ line, a resistance of how many ohms should be connected in series with the bulb ............... $ohm$
A silver and zinc voltameter are connected in series and a current $i$ is passed through them for a time $t$ liberating $W\, gm$ of zinc. The weight of silver deposited is nearly ..............$W$
Twelve wires each having resistance $2 \Omega$ are joined to form a cube. A battery of $6 \mathrm{~V}$ emf is joined across point $\mathrm{a}$ and $\mathrm{c}$. The voltage difference between $e$ and $f$ is.______.V.