Gr.9 Science Electricity Unit Test

STATIC ELECTRICITY

Q: What is static electricity?

A buildup of charges that are NOT moving.

Q: How is static electricity created?

By friction, conduction, or induction.

Q: What is charging by conduction?

Charging by conduction is the process of transferring electric charge from one object to another through direct contact.

Q: What happens when an object gains electrons?

It becomes negatively charged.

Q: What happens when an object loses electrons?

It becomes positively charged.

Q: What happens between like charges?

They repel.

Q: What happens between opposite charges?

They attract.

Q: What type of charging happens when two objects touch?

Charging by conduction.

Q: What type of charging happens without touching?

Charging by induction.

Q: What is electric discharge?

The sudden movement of excess electrons to another place.

CONDUCTORS & INSULATORS

Q: What is a conductor?

A material that allows electrons to move easily.

Q: What is an insulator?

A material that does NOT allow electrons to move easily.

Q: Example of a conductor?

Copper or aluminum.

Q: Example of an insulator?

Rubber, plastic, wood.

CURRENT ELECTRICITY

Q: What is current electricity?

The flow of electrons in a closed circuit.

Q: What are the four basic parts of a circuit?

Source, load, wires, switch.

Q: What is a load?

A device that uses electrical energy (e.g., bulb).

Q: What is a switch?

A device that opens or closes a circuit.

SERIES VS PARALLEL

Q: What is a series circuit?

A circuit with one path for electrons.

Q: What happens if one component breaks in a series circuit?

The whole circuit stops working.

Q: What is a parallel circuit?

A circuit with multiple paths for electrons.

Q: What happens if one component breaks in a parallel circuit?

The other paths continue working.

OHM’S LAW

Q: Ohm's Law formula?

V = I × R

Q: What does V stand for?

Voltage (volts).

Q: What does I stand for?

Current (amps).

Q: What does R stand for?

Resistance (ohms).

SAFETY

Q: What is a fuse?

A safety device that melts when current is too high.

Q: What is a circuit breaker?

A resettable switch that opens the circuit when current is too high.

Q: What is a GFI (GFCI)?

A safety outlet that detects current leaks and shuts off power.

Q: What is grounding?

A safe path for unwanted electricity to travel into the Earth.

Q: What is the let-go threshold?

The amount of current where muscles freeze and you can’t release an object.

POWER, ENERGY, COST, EFFICIENCY

Q: What is power?

The rate of electrical energy use.

Q: Power formula?

P = V × I

Q: What unit is electric energy billed in?

Kilowatt-hours (kWh).

Q: Efficiency formula?

(Useful energy ÷ input energy) × 100%

CELLS + SOURCES

Q: What is a primary cell?

A non-rechargeable battery. (ex. alkaline battery)

Q: What is a secondary cell?

A rechargeable battery. (ex. Lithium-ion battery)

Q: What is AC?

Alternating current — changes direction repeatedly.

Q: What is DC?

Direct current — flows in one direction.

ONTARIO ELECTRICITY

Q: Main electricity sources in Ontario?

Nuclear, hydro, natural gas, wind, solar.

Q: Why not rely on fossil fuels?

They pollute more and are less sustainable.

ENERGY CONSERVATION

Q: Give one way to conserve electrical energy.

Use LED bulbs.

Q: What is an EnerGuide label?

A label showing average yearly energy use of an appliance.

Electrical Resistence

The opposition to movement of electrons through a circuit.

Resistors

Used to control the flow of electrons in circuits. (ex. nichrome wires)

How does a rotating turbine work.

-Turns a coil inside a magnetic field.

-Coil movement induces electric current.

-Current sent to power lines.

-electricity delivered to homes.

Q: What is Ohm’s Law?

Ohm’s Law states that the voltage across a component equals the current through it multiplied by its resistance (V = I × R).