Standard circuit symbols

Recognise and use the examination circuit symbols for conductors crossing without a connection, a junction, open switch, cell, battery, DC and AC power supplies, transformer, ammeter, voltmeter, fixed and variable resistors, heater, thermistor, light-dependent resistor (LDR), diode, light-emitting diode (LED), lamp, loudspeaker, microphone, electric bell, earth or ground, motor, generator, and fuse or circuit breaker. Other internationally agreed symbols may be accepted in answers.