List of top Physics Questions on Electricity

Figure shows a circuit consisting of cell of emf \(E\) and internal resistance \(r\) connected in series with external resistance \(R\). When \(R = 5\Omega\), current \(i = 1\,A\) and when \(R = 2\Omega\), current \(i = 2\,A\). Find \(r\) (in ohm). 

Find the voltage across the capacitor in steady state. 

If across a resistance, voltage applied is \((20 \pm 0.2)\,\text{V}\) and the current passing through it is \((10 \pm 0.1)\,\text{A}\). Find the maximum error in resistance.
Complete the following: A substance whose resistance becomes almost negligible at a temperature near absolute zero is called a __________.
If 5A current flows through an electric iron, it produces 50J heat in one second, the potential across the electric iron will be
The resistor of resistance \(R\) is connected between the terminals of a cell of emf \(E\) and internal resistance \(r\). The current \(I\) through the circuit is
In a series circuit, if the resistance is doubled, what happens to the current?