Circuits
What system is needed for a light bulb to turn on?
A complete (closed) circuit.
How do opposite charges interact with each other?
They attract.
A toaster transfers more electrical energy each second than a phone charger. Which device has greater power?
The toaster.
When electricity demand is greater than electricity supply, what can happen?
A power outage.
Electrical current is the flow of moving _______________.
electrons.
What common safety feature of circuits connects an object to earth to prevent the build-up of electrons?
A ground wire.
How do similar charges interact with each other?
They repel.
A generator stops spinning.
What happens and why?
It stops producing electrical energy because the magnet is no longer in motion.
True or False:
Electricity is stored in the power grid in large amounts.
False.
Why is copper commonly used in electrical wiring?
It is highly conductive due to its free electrons.
True or False:
Opening a switch allows electricity to continue flowing.
False.
What happens when two objects rub against each other?
What is this called?
They gain or lose electrons.
Static electricity.
Name two forms of energy that electrical energy can become in a light bulb.
Light energy and thermal energy.
Name a destination that might receive electricity first during a shortage.
-hospital
-fire station
-water treatment plant
Name two conductors and two insulators.
Metal, water.
Rubber, plastic, glass, wood.
When a magnet spins within a coil of wire, what is produced?
An electric current.
If two charges move closer together, the electric force becomes...
Stronger.
Electric force increases as distance decreases.
What is power?
The rate at which energy is transferred.
Energy over time.
Why might engineers intentionally turn off power to some neighborhoods?
To prevent the entire grid from failing.
Why can a magnet affect the direction of a compass?
The magnetic field of the compass disrupts the magnetic field of the Earth.
A battery, two wires, and a light bulb are connected.
The light bulb does not light.
Give two possible reasons for this.
-loose wire
-open circuit
-dead battery
-burned-out light bulb
Between a pair of larger charges and a pair of smaller charges, which pair has the stronger electric force?
A pair of larger charges.
Electric force increases as charge increases.
How much power (in Watts) is used when 1800 J of energy are transferred in 1 minute.
30 Watts.
A neighborhood suddenly loses power.
List two possible physics reasons this could happen.
-open circuit
-broken transmission line
-demand greater than supply
-generator failure
-safety shutoff
-weather damage
What describes the relationship between the distance, charge, and electric force of two objects that are near each other?
Coulomb's Law