science 4/4 Flashcards by Anya O'Malley White

What is an electromagnet?

A magnet created by wrapping a coil of wire with a current running through the core material that is easily magnetized (like iron).

More wraps = Stronger magnetic field.

How well did you know this?

Not at all

Perfectly

A magnetic field produced by a current has/can…

(Hint! 4 answers)

has strength and direction
can be turned on or off
can have directions reversed
can have the strength changed

How well did you know this?

Not at all

Perfectly

Why is the electromagnet extremely useful?

It can be turned off and on

How well did you know this?

Not at all

Perfectly

What produces a magnetic field?

An electric current

How well did you know this?

Not at all

Perfectly

Any wire that has an electrical current ____________ through it is surrounded by a ___________________. The magnetic field around the wire forms a __________

What is an example?

First blank: Flowing
Second Blank: Magnetic Field.
Third Blank: Circle

An example: Compass

How well did you know this?

Not at all

Perfectly

True or false: Electromagnets are common.

True, electromagnets are common.

How well did you know this?

Not at all

Perfectly

What are 5 examples of electromagnets being used?

MRI Machine
Electric Motors
Earbuds/Headphones/Speakers
Junkyard Cranes
Gernerater

How well did you know this?

Not at all

Perfectly

What is the magnetic field?

The area around the magnet where it’s magnetism can affect other materials.

How well did you know this?

Not at all

Perfectly

The closer the lines of ______________ the stronger the magnetic field.

Force

How well did you know this?

Not at all

Perfectly

What happens if a magnet is cut in half?

2 magnets would be formed, each having a North and South Pole.

How well did you know this?

Not at all

Perfectly

What are magnets?

They are metals that are capable of generating forces of attraction and repulsion. They attract iron and metals like nickel and colbolt.

How well did you know this?

Not at all

Perfectly

What are 3 examples of magnetic objects?

Steel Can
Paper Clips
Iron Nails

How well did you know this?

Not at all

Perfectly

What are 3 examples of nonmagnetic objects?

Plastic
Aluminum
Brass

How well did you know this?

Not at all

Perfectly

Magnetic force is the __________________ or ________________ that arises between __________________ particles because of their ________________.

First Blank: Attraction
Second Blank: Repulsion
Third Blank: Charged
Fourth Blank: Motion

How well did you know this?

Not at all

Perfectly

Opposites ____________ and like ends ____________.

First Blank: Attract
Second Blank: Repel

How well did you know this?

Not at all

Perfectly

How is a bar magnet like Earth’s magnetic field?

Earth’s Magnetic field is strongest at the poles.

How well did you know this?

Not at all

Perfectly

The magnetic pole of earths ______ is a ______ pole. The _______ pole of compasses attracts to it.

First Blank: North
Second Blank: South
Third Blank: North Pole

How well did you know this?

Not at all

Perfectly

How come a students weight is different on the earth than compared to the moon?

The moon has a less gravitational pull, compared to the earth. The earth is pulling them to the core, thus they weigh more. Weight is determined by weight x acceleration.

How well did you know this?

Not at all

Perfectly

What are the 2 main factors that affect the strength of the gravitational forces. How about the third one?

The mass and the distance affect the gravitational force’s strength. The density also plays a role in the gravitational pull, for the denser the plant, the greater force.

How well did you know this?

Not at all

Perfectly

Why is it that you feel the effect of gravitational forces between you and Earth but not between you and a classmate?

Because Earth has a bigger mass, it has a bigger gravitational pull. A student, depending on their mass has a very low pull, if any.

How well did you know this?

Not at all

Perfectly

What do you think the long, thin arrows represent in a force diagram?

The long, thin arrows represent the gravitational field.

What part of a force diagram indicates where the gravitational fields are stronger?

When the arrows are closer and more compact, it shows more pull in that area than others.

What do the bigger arrows outlined in white near the satellites represent in a force diagram?

The bigger show distance and gravitational pull.

What is the purpose of a gravitational field model?

It helps represent the different gravitational field levels and distances compared to the other planets.

How is the strength of a field represented in a force model?

The strength of the fields is determined by the number of arrows pointing to the center of the energy.

How would you expect the arrows in a gravitational field model to appear close to the Sun? What about far away from the Sun near Pluto? What about near a black hole?

There would be fewer arrows further from the sun from Pluto; however, near a blackhole, there are more arrows.

In class Mr. Bostrom has dropped a book with a piece of paper side by side. Then he dropped them with the paper placed on top of the book. Why did the paper flutter to the ground on its own but fell straight to the ground when dropped with the book? Describe forces acting on the book and paper and why they are affecting the objects like they do.

The paper is fluttering to the ground, for it catches more air, going down. However, when placed on the book, the masses combine and fall to the ground faster. This is affecting the paper without the book because it is lighter and has less mass.

What has to line up in a magnet to make a really strong magnetic field?

The electric current force needs to line up with the current for a stronger magnetic field.

Why might magnets get weaker over time when you use them a lot?

The magnets might get weaker over time because the forces eventually get unaligned, getting weaker and weaker.

What does the strength of electric field forces depend on?

The strength of the electric field depends on the number of coils around the nail the more electric charge also depends on the battery.

(Choose the best answer) As electrons move, they make 1. Electromagnets 2. Ferromagnets 3. Magnetic fields 4. Pulsars

3. Magnetic fields

(Choose the best answer) A compass needle responds to a magnetic field because the compass needle is a 1. Motor 2. Transformer 3. Generator 4. Magnet

4. Magnet

(Choose the best answer) The magnetic field around a wire forms a 1. Triangle 2. Square 3. Circle 4. Circle or triangle

3. Circle

(Choose the best answer) Which of these items is NOT needed to build an electromagnet? 1. A magnet 2. A battery 3. Wire 4. Nail

1. A magnet

True or false? An area where a magnetic force can be detected is a magnetic field.

True

True or False? A coil of wire that has a soft iron core and acts as a magnet when an electric current is in the coil is called an electromagnet.

True

True or False? An advantage of an electromagnet is that it cannot be turned off.

False: it is extremely useful for it can be turned on and off.

True or False? Electromagnets are convenient, but not very strong.

False

True or False? Electromagnets are very uncommon.

False

True or False? You can change the direction of a current in an electromagnet.

True

Explain with an example of how magnets or electric currents have force fields that act over a distance. How can they move objects without directly touching them.

Magnets and electric currents create force fields that act over a distance through magnetic and electromagnetic fields. These fields exert forces on objects without physical contact. Ex: Magnets can attract or repel each other, this demonstrates the forces can act over a distance through invisible fields, moving objects indirectly.

What is an electromagnet? How is it different from a regular magnet and how and why might they be useful?

The electric current makes it act like a magnet. An advantage is that the magnet can be turned off at times, so it can let go of certain things when needed.

What design factors do you think need to be considered when designing real parachutes for people?

Size and Shape – Must slow descent and be stable. Material Strength – Durable and tear-resistant. Weight – Lightweight for portability. Opening Mechanism – Quick, reliable deployment. Control – Ability to steer and direct landing. Safety Features – Backup parachutes and emergency systems. Aerodynamics – Minimize drag and turbulence.

Mr. B drops a basketball from the 95th floor of a building. He then drops a basketball from the 100th floor of the same building. In which scenario will the ball reach a higher speed? Explain.

The basketball that was on the 100th floor will reach the higher speed unless it gets to terminal velocity before hitting the ground, then they would get to the same speed.

What factors determine the strength of a magnetic field?

The charge is a main factor that determines the strength of a magnetic field.

Is there any difference in strength between the various size magnets?

The more mass in the magnetic, the more attraction there was between them.

(Measuring Elementary Charges Article Questions) What did Millikan and Harvey set out to measure?

They set out to measure the elementary charge.

(Measuring Elementary Charges Article Questions) If the top metal plate is negatively charged, what is the charge of the droplets that will be attracted to it?

The other plate would be positively changed.

(Measuring Elementary Charges Article Questions) If a droplet has three extra electrons, what is its measured charge?

The charge would change to negative.

(Measuring Elementary Charges Article Questions) The evaporation of oil from droplets during the experiment is a potential source of what?

This is a possible source of error due to inconsistency.

(Measuring Elementary Charges Article Questions) What is an example of “conformity bias” in the article?

An example of conformity bias is when the results are changed just to fit in.