Earth’s liquid outer core of moving molten iron generates a magnetic field that the compass aligns with

Earth’s rotation alone creates wind that turns the compass needle

Large mountains pull on the needle with gravitational force

Ocean tides magnetize the compass needle each day

Like poles repel and opposite poles attract

Like poles attract and opposite poles repel

Both like and opposite poles attract equally

Neither like nor opposite poles exert forces on each other

Magnetic forces act at a distance through a magnetic field

Magnetic forces require direct contact between objects

Magnetic forces only occur when air is moving between magnets

Magnetic forces occur only when an electric current is absent

On objects made of plastic or wood because they are nonmagnetic

On iron nails because iron is nonmagnetic

On steel paperclips because steel is nonmagnetic

Near another magnet at any distance because fields do not extend through air

A coil of wire with electric current that produces a controllable, temporary magnet, unlike a permanent bar magnet

A permanent magnet made only of magnetized iron, identical to a bar magnet

A magnet that works only underwater and is the same as a bar magnet

The same as a bar magnet but without needing any power source

It increases the magnetic field strength around the core

It decreases the magnetic field strength by spreading the field out

It has no effect on field strength if the current stays the same

It only works if the coils are made of aluminum, not copper

An iron core, an insulated wire coil, and a power source (such as a battery) to provide current

A plastic core, a string coil, and a flashlight battery for light

A permanent bar magnet without any wire or power source

A wire alone, because current is not needed to create a magnetic field

Moving electric charges in the wire produce a magnetic field that forms concentric circles around the wire

Static electric charge on the wire creates a magnetic field only at the ends

Only alternating current creates a magnetic field; direct current does not

A magnetic field appears only when the wire is heated by resistance

Series circuits have one path for current through all components; parallel circuits have multiple branches with separate paths

Series circuits have multiple branches; parallel circuits force all current through one path

Both series and parallel circuits always provide the same current to each bulb

Series circuits never go out if one bulb is removed; parallel circuits always do

In series, bulbs become dimmer as more are added because they share voltage; in parallel, bulbs stay about as bright because each branch gets full battery voltage

In series, adding bulbs makes them brighter; in parallel, adding bulbs makes all bulbs go out

In series and parallel, brightness is always the same for any number of bulbs

In parallel, bulbs are always dimmer than in series because current is split

Open means there is a break so no current flows; closed means the path is complete so current flows

Open means the switch is on and current flows; closed means the circuit is turned off

Open means wires touch to complete the circuit; closed means wires are separated

Open and closed mean the same thing in circuits

A single loop with one battery and four bulbs in a line, with a switch open in the loop so current cannot flow

Four separate branches each with a bulb connected across the battery, with a closed switch

A single loop with one battery and four bulbs, and the switch closed to allow current

A battery connected to one bulb only, with no switch shown

Multiple branches each containing one bulb connected across the battery terminals, with a closed switch completing the main path

A single loop with four bulbs in a line and an open switch

A battery connected to four bulbs in series with no switch

Two separate circuits with different batteries for each bulb

$$V=IR$$ ; V is voltage (volts), I is current (amperes), and R is resistance (ohms)

$$I=VR$$ ; I is current (volts), V is voltage (amperes), and R is resistance (ohms)

$$R=\frac{I}{V}$$ ; R is resistance (volts), I is current (ohms), and V is voltage (amperes)

$$P=VI$$ ; P is power (ohms), V is voltage (amperes), and I is current (volts)

$$2.5\,\Omega$$

$$4.8\,\Omega$$

$$9.5\,\Omega$$

$$14.5\,\Omega$$

$$2.0\,\text{V}$$

$$4.8\,\text{V}$$

$$3.3\,\text{V}$$

$$9.0\,\text{V}$$

$$0.5\,\text{A}$$

$$2.0\,\text{A}$$

$$5.0\,\text{A}$$

$$7.5\,\text{A}$$

$$0.3\,\text{A}$$

$$0.6\,\text{A}$$

$$1.7\,\text{A}$$

$$2.5\,\text{A}$$

$$6\,\Omega$$

$$8\,\Omega$$

$$12\,\Omega$$

$$18\,\Omega$$

Increase the number of wire turns around the core

Increase the electric current through the coil

Use a soft iron core instead of no core

Replace the copper wire with thinner, higher‑resistance wire to reduce current

Connect all bulbs in a single series loop

Connect bulbs in parallel branches across the power source

Use a series circuit but add a single switch

Increase the voltage while keeping a series arrangement

Test each item with a magnet and group items by whether they are attracted or not, recording results

Sort items by size and color, then make groups based on appearance

Measure each item’s mass and density to decide which are magnetic

Heat items and group them by melting point as evidence of magnetism

The total resistance becomes infinite

The total resistance decreases

The total resistance increases

The total resistance stays the same

Iron nail

Steel screw

Cobalt coin

Plastic spoon

The bulb lights up because the circuit is complete

The bulb goes out because the circuit is broken

The battery stops working

The bulb explodes due to excess current

All remaining bulbs go out because the circuit is broken

The remaining bulbs get brighter

Only the removed bulb goes out, others stay lit

The brightness of the remaining bulbs stays the same

Glass

Wood

Plastic

Iron

$$9\,\text{V}$$

$$0.8\,\text{V}$$

$$20\,\text{V}$$

$$1.25\,\text{V}$$

resistor

Ammeter

Voltmeter

Switch

series

parallel

Series Circuit

Parallel Circuit

A closed path

A switch

An insulator

Series circuit

Parallel circuit

Direct circuit

Attract

Repel

Do nothing

resistor

Ammeter

Voltmeter

Switch

zig zag

Resistor

Ammeter

Battery

This circuit will work because it is an

open circuit

This circuit will work because it is a

closed circuit

This circuit will not work because it is an

open circuit

This circuit will not work because it is a

closed circuit

Fixed Resistor

Wire

Power Supply

Capacitor

Battery

Lines

Resistor

bulb

open

parallel

closed

battery, switch, bulb, wire

switch, switch, bulb

battery, switch, bulb, motor

The other light bulb will still on

The other light bulb will be off

Both lights will be off

None of the light will be off

Current

Power

Ohms

Watts