Simple Circuits
What is a circuit with no gaps or breaks in it?
open circuit
mechanical circuit
closed circuit
Closed circuit
Which material would make a good insulator of electricity?
copper wire
aluminum foil
rubber tube
gold wire
A material that slows the flow of electricity:
insulator
conductor
short circuit
resistance
insulator
True or False.
Shredding paper is considered a chemical change because the paper is smaller after it is shredded.
False.
The paper is still paper, it hasn't changed into a new substance.
Which is a temporary magnet?
magnetite
bar magnet
electromagnet
horseshoe magnet
Electro-magnet
The part of the circuit through which the electricity flows is the:
wire
battery
light bulb
wire
What item is a good conductor of electricity?
a dice
a nickel
a pencil
magnet
a nickel
____ is a good conductor of electricity.
glass
copper
plastic
Copper
True or False
Water changing into a new state in the water cycle is considered a chemical change.
False.
When water changes from liquid to solid or gas, it is still the same chemical composition of water, the molecules remain the same throughout the process.
The north and south poles of two magnets _______.
repel each other
create friction
attract each other
attract each other.
The part of the circuit that the battery is called:
load
switch
power source
power source
An electrical cord uses ______.
only conductors
only insulators
both conductors and insulators.
both insulators and conductors
___________ keep the electrical charge inside pathways.
* Insulators
* Conductors
* Magnets
Insulators
True or False.
Microwaving a bowl of soup is a physical change.
True.
Although you are adding heat, it is not involving any chemical reactions. It just causes the molecules to move faster and increase the temperature.
True or False.
Magnetism is a force
True
Too much current flowing in a wire can cause:
a fuse
circuit breaker
heat and sparks
heat and sparks
True or False.
Conductors are made of materials that electricity can flow through easily.
True.
Which is a good conductor of electricity?
*Rubber tubes
*Salt water
*Wooden box
Salt water
True or False.
Milk turning sour is a chemical change.
True.
This is because of the action of bacteria producing a type of acid which changes the composition of the milk and it can't be changed back.
What is an important use of magnetism?
It keeps Earth from falling into space.
It keeps you from sliding on the ground.
It is for people to have fun with in labs.
It keeps Earth from falling into space.
In direct current, electric charges _______.
move in reverse directions
move in one direction
do not move
Move in one direction
Why do we use insulators in every day life? Give an example.
Rubber gloves or boots
Rubber handles on pots/pans
Plastic/Rubber tubing around wires
The electrician uses rubber gloves for protection. The purpose of the rubber gloves is:
keep the electrician dry
create an electrical circuit
insulate the electrician
True or False.
When a firefly lights up, it is a physical change.
False.
Fireflies produce light through a chemical reaction called bioluminescence. The molecules inside the fireflies react with an enzyme to produce light. It is not reversible, so that means that it is a chemical change.
What is true?
Magnetism is weakest at the poles of Earth.
Magnetism is strongest at the poles of Earth.
If North and south interact, they will repel.
Magnetism is strongest at the poles of the Earth.