In the given figure, when galvanometer shows no deflection, the current (in $A$) flowing through $5\,\Omega $ resistance will be
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Let current through $5\,\Omega $ resistance be $i$.
Then $i \times 25 = (2.1 - i)\,10$
$i = \frac{{10}}{{35}} \times 2.1 = 0.6\,A$
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Resistance of tungsten wire at $150\,^oC$ is $133\,\Omega $. Its resistance temperature coefficient is $0.0045\,^oC$. The resistance of this wire at $500\,^oC$ will be .............. $\Omega$
What amount of heat will be generated in a coil of resistance $R$ due to a charge $q$ passing through it if the current in the coil decreases to zero uniformly during a time interval $\Delta t$
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Consider a block of conducting material ofresistivity '$\rho$' shown in the figure. Current '$I$' enters at '$A$' and leaves from '$D$'. We apply superp osition principle to find voltage '$\Delta V$ ' developed between '$B$' and '$C$'. The calculation is done in the following steps:
$(i)$ Take current '$I$' entering from '$A$' and assume it to spread over a hemispherical surface in the block.
$(ii)$ Calculatefield $E(r)$ at distance '$r$' from $A$ by using Ohm's law $E = \rho j$, where j is the current per unit area at '$r$'.
$(iii)$ From the '$r$' dependence of $E(r)$, obtain the potential $V(r)$ at $r$.
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For current entering at $A$, the electric field at a distance '$r$'
from $A$ is
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