Electricity and Magnetism Flashcards
A machine that uses magnets and an energy source to produce electricity is a
generator
What kind of circuit allows a current to flow through it?
Closed circuit
Which statement about safety is false?
a) Never touch anything electrical when you are wet.
b) Use a hair dryer with a warn cord
b) Use a hairdryer with a worn cord.
What pole is attracted to the north pole of a magnet?
South
What has a negative electrical charge?
electron
An atom has no electrical charge because…
it has an equal number of protons and electrons
A small magnet that turns freely and always points north is a
compass
Air, rubber, glass and plastic are good..
insulators
A magnetic field is the…
Area around a magnet where the force acts
Rubbing a magnet along a steel needle will make the needle…
A magnet
How does a light bulb use electricity to produce light?
Resistance in the wires of the light bulb cause the wires to get very hot. This head makes the wires glow and produce light.
Why are electromagnets so useful? Name three objects that need electromagnets to work.
Electromagnets are useful because they are easily turned on and off, unlike ordinary magnets. Three objects that need electromagnets to work are cranes, telephones and doorbells.
