bob
which of these best completes the circuit?
rubber band
metal nail
leather shoelace
wooden toothpick
metal nail
. Which of these materials is a good conductor of electricity?
Rubber
Glass
Metal
Newspaper
metal
Electric lights will not come on unless their electrical circuit is a —
open circuit
series circuit
closed circuit
short circuit
closed circuit
Which of these substances conducts electricity the best?
Wood
Brick
Copper
Plastic
copper
What material would be safest to use as an insulator to cover electrical wires?
Aluminum
Tin
Rubber
Water
rubber
A bar magnet is placed on a table, and a sheet of blank paper is placed over the magnet. What could be sprinkled on the paper to show the magnetic field of the bar magnet?
Salt
Iron filings
Sand
Soil
iron filings
To make an electromagnet, a conductor should be coiled around —
a glass tube
an iron nail
a roll of paper
a wooden stick
an iron nail
Michael Faraday showed how electric current in a wire produces —
molecules
chemicals
a vibration
a magnetic field
a magnetic field
Which of these can most easily produce magnetic fields?
Sunlight
Wind
Electricity
Flowing water
electricity
Which energy transformation most likely occurs in a steam iron?
Electrical energy changes to heat energy
Electrical energy changes to sound energy
Mechanical energy changes to heat energy
Mechanical energy changes to light energy
electrical energy changes to heat energy
Copper wire is often wrapped in plastic. Plastic material is a good —
electromagnet
insulator
circuit
current
insulator
many electrical wires are wrapped with a plastic coating because plastic is —
less expensive than steel
more dense than copper
able to keep its shape
a good insulator
a good insulator
Early scientists most likely saw a discharge of electricity for the first time when observing a —
waterfall
rainbow
lightning storm
volcano erupting
lightning storm
Benjamin Franklin conducted this famous experiment that showed lightning was —
a movement of air molecules
a magnetic field
an electrical discharge
a glowing chemical
an electrical discharge
Benjamin Franklin discovered the form of energy produced by lightning. Experiments with lightning killed many people before he discovered that lightning is a form of —
gravity
water
magnetism
electricity
electricity
bits of paper are attracted to the surface of this balloon. What attracts the paper pieces to the balloon?
Friction
Magnetism
Potential energy
Static electricity
static electricity
Which form of energy is being used by the toaster?
Chemical
Electrical
Solar
Nuclear
electrical
The energy used to move most bicycles is an example of what type of energy?
Electrical
Mechanical
Chemical
Nuclear
mechanical
which item is designed to change electrical energy into heat energy?
Alarm clock
Hand dryer
Fan
Telephone
hand dryer
An electric motor is designed to turn electrical energy into —
solar energy
potential energy
static electricity
mechanical energy
mechanical energy
When in operation, this tool transforms electrical energy mostly into —
chemical energy
solar energy
sound energy
mechanical energy
mechanical energy
Many metals, especially copper and aluminum, are good:
conductors
generators
insulators
circuits
conductors
Which of the following are good conductors of electricity?
Cotton
Glass
Paper
Plastic
Steel
Copper
Rubber
Iron
Aluminum
steel aluminum iron copper
Which of the following is not a source of electricity?
A wire
A battery
An outlet
a wire
Any path along which electricity can flow is an:
electric outlet
electric circuit
electric circuit