K323 / 2027

Chapter 14

Current of electricity

Current describes charge passing a point; voltage describes energy transferred per charge.

Choose the correct quantities and measurement points before calculating.

Includes series-source e.m.f., metallic resistance and the I-V characteristics of a wire, lamp and diode. For K323 (2027) / 6091 (2026).

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Choose a topic

  1. Current, charge and electron flow

    Use charge per second, distinguish flow directions and measure current in the chosen branch.

  2. E.m.f. and potential difference

    Use energy per charge, connect a voltmeter and combine correctly oriented series sources.

  3. Resistance and wire dimensions

    Match voltage and current to the same component, then compare wire length and cross-sectional area.

  4. Temperature and I-V characteristics

    Explain metallic resistance changes and interpret wire, lamp and diode graphs.