(i) How is electric current related to the potential difference across the terminals of a conductor ? Draw a labelled circuit diagram to verify this relationship.

(ii) Why should an ammeter have low resistance ?

(iii) Two V - I graphs A and B for series and parallel combinations of two resistors are as shown. Giving reason state which graph shows (a) series, (b) parallel combination of the resistors.

(i) Electric current is directly proportional to the potential difference across the terminals of a conductor. This relationship is known as Ohm's Law, which states that V = IR, where V is the potential difference, I is the current, and R is the resistance of the conductor.

(ii) An ammeter should have low resistance so that it does not affect the current flowing through the circuit. If the ammeter has high resistance, it will reduce the current flowing through the circuit, which can lead to inaccurate readings.

(iii) Graph A shows the series combination of two resistors, while graph B shows the parallel combination of two resistors. In a series combination, the current flowing through each resistor is the same, while in a parallel combination, the voltage across each resistor is the same. Therefore, graph A represents the series combination, and graph B represents the parallel combination.