Electric field at a distance $$r$$ from an infinitely long uniformly charged straight conductor, having linear charge density $$\lambda$$ is $$E_1$$. Another uniformly charged conductor having same linear charge density $$\lambda$$ is bent into a semicircle of radius $$r$$. The electric field at its centre is $$E_2$$. Then
A wire of resistance $$R$$ is connected across a cell of emf $$(\varepsilon)$$ and internal resistance $$(r)$$. The current through the circuit is $$I$$. In time $$t$$, the work done by the battery to establish the current $$I$$ is
For a given electric current the drift velocity of conduction electrons in a copper wire is $$v_d$$ and their mobility is $$\mu$$. When the current is increased at constant temperature
Ten identical cells each emf $$2 \mathrm{~V}$$ and internal resistance $$1 ~\Omega$$ are connected in series with two cells wrongly connected. A resistor of $$10 ~\Omega$$ is connected to the combination. What is the current through the resistor?