Complete the following sentences:
(i) An electric current represents a flow of electrical __________ inside a metal wire.
(ii) The instrument connected in series to measure this current is called __________ .
(iii) The potential difference across a component can be measured by connecting __________ in parallel with the component.
A student connects a length of resistance wire in a simple series circuit. The current through the wire is 0.6 A0.6\text{ A}0.6 A and the potential difference across it is 13.2 V13.2\text{ V}13.2 V. Calculate the resistance of this wire and state the unit.
The wire in (b) is replaced by a shorter length of wire from the same reel. Without further calculation, state the effect this has on:
(i) the resistance of the wire,
(ii) the current in the new wire when the potential difference across it remains 13.2 V13.2\text{ V}13.2 V.
452 exam-style questions on CIE IGCSE Physics 4.2 Electrical quantities, covering 4.2.1a Positive and negative charge, 4.2.1b Charging by friction and detecting charge, 4.2.1c Electrical conductors and insulators, 4.2.1d Electric fields and electric field patterns, 4.2.2a Electric current, charge and measuring current, 4.2.2b Conduction in metals and the direction of current, 4.2.2c Direct current and alternating current, 4.2.3a Electromotive force, 4.2.3b Potential difference and voltmeters, 4.2.4a Resistance, 4.2.4b Resistance of a metallic wire, 4.2.4c Current–voltage graphs, and 4.2.5 Electrical energy and electrical power. Each one has a worked solution and a mark scheme showing where the marks go.