Question

Draw a schematic diagram of a circuit consisting of a battery of four 1·5 V cells, a 5 Ω resistor, a 10 Ω resistor and a 15 Ω resistor and a plug key, all connected in series. Now find (I) the electric current passing through the circuit, and (II) potential difference across the 10 Ω resistor when the plug key is closed.

When is the potential difference between two points said to be 1 volt?

A copper wire has a diameter of 0·2 mm and resistivity of 1·6 × 10⁻⁸ Ω m. What will be the length of this wire to make its resistance 14 Ω? How much does the resistance change, if the diameter of the wire is doubled?

Two wires A and B of same material, having same lengths and diameters 0·2 mm and 0·3 mm respectively, are connected one by one in a circuit. Which one of these two wires will offer more resistance to the flow of current in the circuit ? Justify your answer.