To supply electricity from a remote wind farm to a distant city, an energy company must transmit electrical power over long distances. Which combination of current type, voltage level, and benefit is correct for this transmission?
| Type of Current | Voltage Level | Benefit | |
|---|---|---|---|
| A | Alternating current (AC) | High voltage | Reduces energy lost as heat in the cables |
| B | Alternating current (AC) | Low voltage | Increases the current for faster transmission |
| C | Direct current (DC) | High voltage | Decreases the electrical resistance of the cables |
| D | Direct current (DC) | Low voltage | Eliminates the need for substation transformers |
Alternating current (AC) | High voltage | Reduces energy lost as heat in the cables
Alternating current (AC) | Low voltage | Increases the current for faster transmission
Direct current (DC) | High voltage | Decreases the electrical resistance of the cables
Direct current (DC) | Low voltage | Eliminates the need for substation transformers
275 exam-style questions on CIE IGCSE Physics 4.5 Electromagnetic effects, covering 4.5.1a Electromagnetic induction, 4.5.1b Direction of an induced e.m.f., 4.5.2 The a.c. generator, 4.5.3a Magnetic effect of a current and its applications, 4.5.3b Strength and direction of the field around wires and solenoids, 4.5.4a Force on a current-carrying conductor, 4.5.4b Force on beams of charged particles, 4.5.5 The d.c. motor, 4.5.6a Construction and operation of a transformer, 4.5.6b Turns ratio and current in a transformer, and 4.5.6c High-voltage transmission of electricity. Each one has a worked solution and a mark scheme showing where the marks go.