S4w4 magnets and ACDC

Last updated 8 months ago

27 questions

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S4w4 magnets and ACDC

Last updated 8 months ago

27 questions

Questions 1-3

02:16

Questions 4 & 5

02:41

1

Circular magnetic field lines don't seem overly useful, but you can do lots of things with wires. Let's say we wrap a wire in a coil.
in your mind's eye, let your thumb move along this coil. What happens to you your magnetic field lines shown by your other fingers as you move along the coil?

Questions 9 & 10

01:14

Question 11

01:31

1

Do you have any questions?

Required

2

A magnet produces a magnetic field. Which diagram shows the magnetic field pattern around a bar magnet? Select the correct diagram by checking the box to the right of the diagram. Pay special attention to which way the arrows are pointing in each diagram.

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1

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1

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1

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1

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1

What is created when a current is run through a coil of wire wrapped around an iron core? (type one word only)

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2

Explain the difference between a motor and a generator?

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1

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What does the block that is in the middle of your computer charging cable do?

1

If a bar magnet were thrown through a coil of wires, the magnet would slow down. Why?

1

Questions 1-3

02:16

Questions 4 & 5

02:41

The previous image shows gravitational field lines, They show the direction of the force created by the mass of the planet. Magnetic field lines are similar, but their field lines are

Always in loops

Always from north to south, there is no such think as a single north or single south monopole. 

Current carrying wires create magnetic fields, but those magnet field loops go in a very specific direction. When you put the thumb of your right hand towards the direction of the current, look at the direction of your other four fingers - they curl in a circle. That circle is the direction of the magnetic field lines induced by the current.
A vertical wire carries a current straight down. To the east of this wire, the magnetic field points. Use the right hand rule as shown here.

Circular magnetic field lines don't seem overly useful, but you can do lots of things with wires. Let's say we wrap a wire in a coil.
in your mind's eye, let your thumb move along this coil. What happens to you your magnetic field lines shown by your other fingers as you move along the coil?

Questions 9 & 10

01:14

Question 11

01:31

Do you have any questions?

A magnet produces a magnetic field. Which diagram shows the magnetic field pattern around a bar magnet? Select the correct diagram by checking the box to the right of the diagram. Pay special attention to which way the arrows are pointing in each diagram.

Similar poles of a magnet repel each other.

True

False

All metals are magnetic.

True

False

If a magnet with two poles is cut in half, it will have only one pole

True

False

Which of the following creates a magnetic field?

Two wires next to each other

A piece of aluminum

A coil of wire carrying current

A plastic insulator

What is created when a current is run through a coil of wire wrapped around an iron core? (type one word only)

Explain the difference between a motor and a generator?

A magnetic force cannot act on an electron when it moves...

at an angle between 90 degrees and 180 degrees to the magnetic field lines.

parallel to the magnetic field lines.

perpendicular to the magnetic field lines.

at an angle between 45 degrees and 90 degrees to the magnetic field lines.

What is the difference between the movement of the two electrons when comparing the two types of currents - Alternating current and direct current?

There's no difference.

An Alternating Currents electrons move in one direction while a Direct Currents electrons move back and forth.

An Alternating Currents electrons move back and forth while a Direct Currents electrons move in one direction.

An Alternating Currents electrons move back and forth while a Direct Currents electrons don't move at all.

What type of current do you get out of a battery?

AC

DC

What sort of current do you get out of a wall socket?

AC

DC

What does the block that is in the middle of your computer charging cable do?

If a bar magnet were thrown through a coil of wires, the magnet would slow down. Why?

The ratio of the volts to number of turns on the primary coil has to equal the ratio of volts to turns of the secondary coil. A cd player requires twelve volts to operate. A transformer with 500 turns on the primary turns 120 volts into 12 volts. How many turns should the secondary have?

500/120 = 12/x ---> x=1440/500 = 2.88

500(120)=12x ---> x=5000

120/500 = 12/x ---> x= 50

120+500 = 12+x ---> x = 608

How are you feeling about each of these?

what is a magnet
what is a domain in magnetism
field lines
inducing current with magnets
inducing magnetic fields with electricity
motors vs generators
difference between AC and DC power
how transformers work
calculating the number of turns to get the right step up/step down

I got this
I'm fuzzy
so confused

Are all iron objects magnetic - as in do they create a magnetic field and attract/repulse objects

yes

no

go find a magnet and a couple iron nails or needles. Any fridge magnet will do. take the magnet and stroke it in one direction along the nail. The stronger the magnet, the stronger the effect. See if the stroked nail/needle now attracts the other nail/needle. What happens?

What's happening in the nail is that that all those magnetic domains are scattered higgledy-piggledy in all directions. By exposing the domains to a magnet stroking along the surface of the nail, you care coaxing all those little domain to align with the motion of the magnet. use the nail to attract different bits of iron for a bit, and you will notice the effect wear off. What do you think it happening that makes the needle not a magnet?

We started electrostatics by comparing the force between two charges to the gravitational force between two planets. We discussed that the equations for the forces themselves are very similar. Consider the following image showing a gravitational field near the earth and the moon.
What do you think happens at point N?

The object at N will be moved in a direction normal to the image

the object at N has equal and opposite forces pulling it towards both the moon and the earth

the object at N falls towards the moon

the object at N falls towards the earth

When we discussed circuits, we mentioned a capacitor. A capacitor is just two plates with a something between them. Charge builds on one side, and the opposite charge builds on the other side. This would create an electric field line that looks like this
What would you guess a compass placed in this field would do?

The previous image shows gravitational field lines, They show the direction of the force created by the mass of the planet. Magnetic field lines are similar, but their field lines are 

Always in loops

Always from north to south, there is no such think as a single north or single south monopole. 

Current carrying wires create magnetic fields, but those magnet field loops go in a very specific direction. When you put the thumb of your right hand towards the direction of the current, look at the direction of your other four fingers - they curl in a circle. That circle is the direction of the magnetic field lines induced by the current. 
A vertical wire carries a current straight down. To the east of this wire, the magnetic field points. Use the right hand rule as shown here. 

toward the north.

toward the east.

toward the west.

toward the south.

downward.

having an iron bolt is important to having a strong electromagnet, but a coil without a iron core will work too, but not be nearly so strong. why do you think that is?

The more turns on your electromagnet, the stronger your electromagnet. Why do you think that is?

do you think this electromagnet would work if there was no insulation on the wire in the coil? why or why not?

Similar poles of a magnet repel each other.

True

False

All metals are magnetic.

True

False

If a magnet with two poles is cut in half, it will have only one pole

True

False

Which of the following creates a magnetic field?

Two wires next to each other

A piece of aluminum

A coil of wire carrying current

A plastic insulator

A magnetic force cannot act on an electron when it moves...

at an angle between 90 degrees and 180 degrees to the magnetic field lines.

parallel to the magnetic field lines.

perpendicular to the magnetic field lines.

at an angle between 45 degrees and 90 degrees to the magnetic field lines.

What is the difference between the movement of the two electrons when comparing the two types of currents - Alternating current and direct current?

There's no difference.

An Alternating Currents electrons move in one direction while a Direct Currents electrons move back and forth.

An Alternating Currents electrons move back and forth while a Direct Currents electrons move in one direction.

An Alternating Currents electrons move back and forth while a Direct Currents electrons don't move at all.

What type of current do you get out of a battery?

AC

DC

What sort of current do you get out of a wall socket?

AC

DC

The ratio of the volts to number of turns on the primary coil has to equal the ratio of volts to turns of the secondary coil. A cd player requires twelve volts to operate. A transformer with 500 turns on the primary turns 120 volts into 12 volts. How many turns should the secondary have?

500/120 = 12/x ---> x=1440/500 = 2.88

500(120)=12x ---> x=5000

120/500 = 12/x ---> x= 50

120+500 = 12+x ---> x = 608

How are you feeling about each of these?

what is a magnet

what is a domain in magnetism

field lines

inducing current with magnets

inducing magnetic fields with electricity

motors vs generators

difference between AC and DC power

how transformers work

calculating the number of turns to get the right step up/step down

I got this

I'm fuzzy

so confused

Are all iron objects magnetic - as in do they create a magnetic field and attract/repulse objects 

yes

no

We started electrostatics by comparing the force between two charges to the gravitational force between two planets. We discussed that the equations for the forces themselves are very similar. Consider the following image showing a gravitational field near the earth and the moon.
What do you think happens at point N?

The object at N will be moved in a direction normal to the image

the object at N has equal and opposite forces pulling it towards both the moon and the earth

the object at N falls towards the moon

the object at N falls towards the earth

S4w4 magnets and ACDC

S4w4 magnets and ACDC

Circular magnetic field lines don't seem overly useful, but you can do lots of things with wires. Let's say we wrap a wire in a coil. in your mind's eye, let your thumb move along this coil. What happens to you your magnetic field lines shown by your other fingers as you move along the coil?

Do you have any questions?

A magnet produces a magnetic field. Which diagram shows the magnetic field pattern around a bar magnet? Select the correct diagram by checking the box to the right of the diagram. Pay special attention to which way the arrows are pointing in each diagram.

What is created when a current is run through a coil of wire wrapped around an iron core? (type one word only)

Explain the difference between a motor and a generator?

What does the block that is in the middle of your computer charging cable do?

If a bar magnet were thrown through a coil of wires, the magnet would slow down. Why?

The previous image shows gravitational field lines, They show the direction of the force created by the mass of the planet. Magnetic field lines are similar, but their field lines are

Circular magnetic field lines don't seem overly useful, but you can do lots of things with wires. Let's say we wrap a wire in a coil. in your mind's eye, let your thumb move along this coil. What happens to you your magnetic field lines shown by your other fingers as you move along the coil?

Do you have any questions?

A magnet produces a magnetic field. Which diagram shows the magnetic field pattern around a bar magnet? Select the correct diagram by checking the box to the right of the diagram. Pay special attention to which way the arrows are pointing in each diagram.

Similar poles of a magnet repel each other.

All metals are magnetic.

If a magnet with two poles is cut in half, it will have only one pole

Which of the following creates a magnetic field?

What is created when a current is run through a coil of wire wrapped around an iron core? (type one word only)

Explain the difference between a motor and a generator?

A magnetic force cannot act on an electron when it moves...

What is the difference between the movement of the two electrons when comparing the two types of currents - Alternating current and direct current?

What type of current do you get out of a battery?

What sort of current do you get out of a wall socket?

What does the block that is in the middle of your computer charging cable do?

If a bar magnet were thrown through a coil of wires, the magnet would slow down. Why?

The ratio of the volts to number of turns on the primary coil has to equal the ratio of volts to turns of the secondary coil. A cd player requires twelve volts to operate. A transformer with 500 turns on the primary turns 120 volts into 12 volts. How many turns should the secondary have?

How are you feeling about each of these?

Are all iron objects magnetic - as in do they create a magnetic field and attract/repulse objects

go find a magnet and a couple iron nails or needles. Any fridge magnet will do. take the magnet and stroke it in one direction along the nail. The stronger the magnet, the stronger the effect. See if the stroked nail/needle now attracts the other nail/needle. What happens?

The more turns on your electromagnet, the stronger your electromagnet. Why do you think that is?

do you think this electromagnet would work if there was no insulation on the wire in the coil? why or why not?

Circular magnetic field lines don't seem overly useful, but you can do lots of things with wires. Let's say we wrap a wire in a coil.
in your mind's eye, let your thumb move along this coil. What happens to you your magnetic field lines shown by your other fingers as you move along the coil?

Circular magnetic field lines don't seem overly useful, but you can do lots of things with wires. Let's say we wrap a wire in a coil.
in your mind's eye, let your thumb move along this coil. What happens to you your magnetic field lines shown by your other fingers as you move along the coil?