Section: Natural Sciences

24) When electricity flows through a wire wound in the form of a coil, the coil functions as

1. a resistor
2. a generator
3. an electromagnet
4. an electroscope
5. an electrostatic generator

The magnetic field around any long straight wire is circular when an electric current passes through the wire. If an electric current is passed through a coil of wire, the strength of the magnetic field is equal to the number of coils of wire and the amount of current in the coil.