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Flashcards in Electric and Magnetic Fields Deck (15)
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1
Q

What is causes static charge?

A

Friction

2
Q

If you rubbed metal with a cloth, would you get static charge.

A

No, because 2 insulators must be rubbed together to create a static charge

3
Q

How do plastic rods become positively charged?

A

When They are rubbed by a cloth, the electrons are rubbed off the plastic rod and transferred onto the cloth, making the rod positively charged.

4
Q

Gives one use of static charge.

A

Electrostatic sprayers

Photocopiers

5
Q

Give two dangers of static charges.

A

Sparks when refuelling cars and airplanes, lightening

6
Q

How does earthing things reduce the risk of a spark

A

It is allows the charge that built up to escape, isolating the system.

7
Q

Do electronic field lines go from positive to negative or negative to positive.

A

Positive to negative

8
Q

Do magnetic field lines do form S to N or N to S.

A

N to S

9
Q

What can be used to show the magnetic field lines?

A

Iron filings or a plotting compass.

10
Q

Give the only 3 metals that are magnetic.

A

Iron, Nickel and cobalt

11
Q

Give 5 uses of magnets

A

Fridge doors, Cranes, Maglev trains, MRI scanners and doorbells

12
Q

What is the Right Hand Rule?

A

Thumb shows direction of current and fingers the direction of the field.

13
Q

What does each finger in the Left Hand Rule represent/

A

Thumb is the Motion, First Finger is the Field and The second finger is the Current.

14
Q

What is the equation to find the Force acting on a wire at 90 degrees to the field.

A

F=BIl

15
Q

Calculate the force on a 20cm wire if 1.2A of current is flowing and the magnetic flux density is 0.5T.

A

0.12N