AKS 10 Review - Electricity and Magnetism

Multiple Choice

what kind of circuit is this?

• parallel

• series

• chris barton

• open

Ohm's Law

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An improved electromagnet

• Here is a way to make a stronger electromagnet

• Wrap the wire around a piece of iron called a core

• Iron is a magnetic material. When a current flows in the coil, the iron becomes magnetised making the magnetic field much stronger

• _{Would a wooden core work?}

Multiple Choice

Which makes an electromagnet work?

• needle

• electricity

• pin

• thumbtacks

Circuit Symbols

• Battery

• Bulb

• Switch

• Resistor

Parallel circuits

• There are several pathways or loops through the circuit

• Electrons flow through just one of those pathways

• If one bulb burned out, the rest of the bulbs would still glow

Multiple Choice

In a parallel circuit if one of the light bulbs burns out the rest _________.

• stop the flow of electricity

•  can still light up

•  will go out

• of the light bulbs burn out also

Ohm's Law - V=IR

• Shows the relationship between current, voltage, and resistance

• V is for VOLTAGE (volts)

• I is for CURRENT (amps)

• R is for RESISTANCE (ohms)

Example 3

• How much current would flow through a circuit with 25 ohms of resistance and 100 volt battery?

Circuits and Ohm's Law

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Multiple Choice

A permanent magnet will always be magnetic.

• True

• False

Switching on and off

• It is easy to switch electricity on and off. This means we can switch an electromagnet on and off

• _{Can you think of any potential uses for a magnet you can turn on and off?}

Circuit Symbols

• Battery

• Bulb

• Switch

• Resistor

Types of Circuits

• Series Circuits

• Parallel circuits

Types of Circuits

• Series Circuits

• Parallel circuits

Circuit Symbols

• Battery

• Bulb

• Switch

• Resistor

Example 2

• There are 4 amps of current flowing through a circuit with a 12 volt battery. How much resistance is in the circuit?

There are other types of magnets too

• An electromagnet works using electricity

• It can be turned on or off

Switching on and off

• Cranes are used in scrap yards where heavy, metal objects are moved by a electromagnets on the cranes (not hooks)

• In the first picture, the crane driver turns on the electromagnet to lift the old car

• When the car is over the correct position, the driver turns off the magnet to drop the car

Series circuits

• All elements in the circuit are in one loop

• Every electron flow through every element

• If one bulb burned out, the rest would also go out

Series circuits

• All elements in the circuit are in one loop

• Every electron flow through every element

• If one bulb burned out, the rest would also go out

Multiple Choice

This is an example of a ______ circuit

• Series
• Parallel
• Open
• Dihexihedral

Parallel circuits

• There are several pathways or loops through the circuit

• Electrons flow through just one of those pathways

• If one bulb burned out, the rest of the bulbs would still glow

Multiple Choice

What kind of circuit is this?

• series
• parallel

Multiple Choice

This is an example of a ______ circuit

• Series

• Parallel

• Open

• Dihexihedral

Multiple Choice

What is the type of circuit that stops working when one bulb goes out?

• A broken circuit

• Parallel Circuit

• Series Circuit

• A metal circuit

Multiple Choice

what kind of circuit is this?

• parallel

• series

• chris barton

• open

Multiple Choice

In a parallel circuit if one of the light bulbs burns out the rest _________.

• stop the flow of electricity

•  can still light up

•  will go out

• of the light bulbs burn out also

Ohm's Law - V=IR

• Shows the relationship between current, voltage, and resistance

• V is for VOLTAGE (volts)

• I is for CURRENT (amps)

• R is for RESISTANCE (ohms)

Voltage (V)

• Comes from the battery or another voltage source

• The "push" that moves electrons around the circuit

• Think of it like a water pump - without the pump, the water would just sit in the pipe and not move anywhere

Current (I)

• Electrons in the circuit flowing or moving around the circuit

• Measured in amps

• When electrons move faster, the current is greater

• Like the water flowing through a pipe

Resistance (R)

• Makes it harder for electrons to flow through the circuit

• Measured in Ohms

• Kind of like friction or sand that slows the water in the pipe down

Ohm's Law

​

Example 1

• There are 4 amps of current flowing through a circuit with 2 ohms of resistance. How much voltage did the battery provide?

Example 2

• There are 4 amps of current flowing through a circuit with a 12 volt battery. How much resistance is in the circuit?

Example 3

• How much current would flow through a circuit with 25 ohms of resistance and 100 volt battery?

Multiple Choice

What is the resistance of a lightbulb that experiences 9 Volts and 3 amps of current?

• 1/3 ohms

• 3 ohms

• 27 ohms

• 9 ohms

Multiple Choice

What is the current in a circuit with 6 ohms of resistance and a battery containing 24 Volts?

• 1/4 A

• 144 A

• 4 A

• 0.4 A

Multiple Choice

What is the voltage of a circuit with 4 ohms of resistance and 3 amps of current?

• 12 V

• 21 V

• 4/3 V

• 3/4 V

Multiple Choice

What is a closed path for electrons to flow through?

• static electricity
• circuit
• amperes

Making an Electromagnet

Multiple Choice

Identify the conductor below.

• cloth rag
• plastic bottle
• gold ring

Multiple Choice

A permanent magnet will always be magnetic.

• True

• False

Multiple Choice

Identify the insulator below.

• aluminum foil
• paperclip
• rubber eraser

There are other types of magnets too

• An electromagnet works using electricity

• It can be turned on or off

Multiple Choice

As the resistance in a circuit increases, the electric current __________.

• increases
• decreases
• stays the same

Electromagnets

• An electromagnet is easy to make

• We need a coil of wire and a battery (or low voltage power supply

• We use the wire coil and battery to make an electric current flow through the coil

Multiple Choice

Electricity is the flow of _________.

• protons
• neutrons
• electrons

Switching on and off

• It is easy to switch electricity on and off. This means we can switch an electromagnet on and off

• _{Can you think of any potential uses for a magnet you can turn on and off?}

Multiple Choice

What type of circuit is pictured?

• series
• Parallel

Switching on and off

• Cranes are used in scrap yards where heavy, metal objects are moved by a electromagnets on the cranes (not hooks)

• In the first picture, the crane driver turns on the electromagnet to lift the old car

• When the car is over the correct position, the driver turns off the magnet to drop the car

Multiple Choice

What type of circuit is pictured?

• series
• parallel

Multiple Choice

is the opposition to the flow of charges in a material.

• Resistance

• Voltage

• Time

• Current

An improved electromagnet

• Here is a way to make a stronger electromagnet

• Wrap the wire around a piece of iron called a core

• Iron is a magnetic material. When a current flows in the coil, the iron becomes magnetised making the magnetic field much stronger

• _{Would a wooden core work?}

Multiple Choice

What would happen if in a circuit the voltage is increase?

• The time would increase

• The current would increase

• The current would decrease

• The current would stay the same

Multiple Choice

What would happen if in a circuit, the resistance increases but the voltage stays the same?

• The current would decrease

• The current would increase

• The voltage would decrease

• The voltage would increase

Multiple Choice

It is a kind of magnet that works only when there is a flow of electricity.

• Electromagnet

• Bar Magnet

• Horse Shoe Magnet

• Magnetite

Multiple Choice

In order to electrical current to flow through a wire the wire must be connected in a ____________ that includes a source of electrical current.

• averager matter

• Complete loop

• In an incomplete loop

• Interrupted Circuit

Multiple Choice

Which of the following is NOT part of an electromagnet?

• wire

• core

• battery

• needles

Multiple Choice

Why electrical wiring usually are covered with a layer of plastic?

• To make it look pretty

• To help electricity flow along the wire

• To make it safe

• To add more energy

Multiple Choice

An electromagnet differs from a permanent magnet because

• permanent magnets require an electrical current to produce a field.

• electromagnets can be turned off or weakened by reducing to stopping the flow of current.

• electromagnets only have one pole, while permanent magnets always have two.

• permanent magnets require the movement of electrons, while electromagnets do not.

Multiple Choice

What needs to be done to this circuit so that the lamp lights up?

• Close the switch

• Add a source and close the switch

• Add another lamp

• Add another lamp and a switch

Multiple Choice

An electromagnet can be strengthened if

• less coils are added to the iron core

• the iron core is removed

• more current runs through the wire

• a nickel or cobalt iron core is used.

Multiple Choice

If lamp 1 is unscrewed from its holder, what will happen to lamp 2?

• It will get brighter

• It will stay the same brightness

• It will go out

• Nothing will happen

Multiple Choice

Electromagnets are ___________________.

• permanent

• instant

• temporary

• stable

Multiple Choice

If lamp 2 is unscrewed from its holder, what will happen to lamp1?

• It will stay lit

• It will go out

• It will get dimmer

• It will dissapear

Multiple Choice

Which makes an electromagnet work?

• needle

• electricity

• pin

• thumbtacks

Multiple Choice

this circuit is .....?

• open
• parallel
• closed
• The cutest little circuit evah!

Multiple Choice

Which of these forces can be used in a motor?

• magnetism

• wind

• friction

• gravity

Multiple Choice

Which appliance does NOT use electromagnet?

• telephone

• television

• radio

• broom