11) Static Electricity

Question 1

What is charge measured in?

Answer 1

Coulombs (C)

Question 2

When do objects become charged?

Answer 2

When they gain or lose electrons

Question 3

What happens to like charges?

Answer 3

They repel

Question 4

What happens to unlike charges?

Answer 4

They attract

Question 5

What happens to an object that becomes negatively charged?

Answer 5

It gains electrons

Question 6

What does a difference between the positive and negative charge of two objects cause there to be?

Answer 6

A potential difference between objects

Question 7

What does the potential difference between two oppositely charged objects cause?

Answer 7

Rapid energy transfer

Spark produced

Question 8

What causes lightning?

Answer 8

Charge building up in clouds producing a spark

Question 9

What does rubbing an object do to the electrons?

Answer 9

Electrons can jump from one object to the other

Both objects become charged

Question 10

How can a plastic rod or balloon be charged?

Answer 10

Rubbing it with a cloth or hair

Question 11

What can a charged plastic rod attract?

Answer 11

A gentle stream of water from a tap

Question 12

What can a charged plastic rod move?

Answer 12

An empty aluminium can

Question 13

Where do conductors allow charge to flow to?

Answer 13

Earth

Question 14

Why can’t conductors maintain a charge?

Answer 14

The charge flows to Earth

Question 15

What are isolated objects?

Answer 15

Objects with no conducting path

Question 16

What are 2 uses of static electricity?

Answer 16

Insecticide spraying

Photocopying

Question 17

How does insecticide spraying work with static electricity?

Answer 17

1) Insecticide is given an electrostatic charge when released
2) Insecticide then attracted to earth so moves away from the sprayer
3) Repulsion between droplets means they don’t clump together
4) Gives an even layer of insecticide to ground

Question 18

What are advantages of using static electricity in pesticide spraying?

Answer 18

Less pesticide lost

Evenly distributed

Question 19

How does photocopying work with static electricity?

Answer 19

Areas to receive ink are positively charged and ink is negatively charged
Ensures even coat of ink in the right places

Question 20

Why is fuelling a car at risk to sparking?

Answer 20

Fuel pumped through hose rubs against car

Electrostatic charge builds up due to friction

Question 21

What do imperfections and gaps in fuelling hoses risk?

Answer 21

Charged fuel can escape as vapour

Spark can ignite vapour and cause an explosion

Question 22

What stops fuel hoses from the risk of sparking?

Answer 22

Earthing the hose

Question 23

What causes electric shocks?

Answer 23

Touching charged objects cause current to flow from the object to you

Question 24

What happens to 2 objects in static electricty?

Answer 24

One becomes positive

One becomes negative

Question 25

What do charged objects create around them?

Answer 25

Electric fields

Question 26

What happens if an electrically charged object enters an electric field?

Answer 26

It feels the force acting on it

Question 27

What is the direction of arrows on an electric field diagram?

Answer 27

The direction positively charged objects would move

Question 28

How does the distance from a charged object affect the strength of the electric field?

Answer 28

The closer to the object, the stronger the electric field

Question 29

What affect does a higher charged object have on the strength of an electric field?

Answer 29

The electric field will be stronger

Question 30

What are point charges?

Answer 30

The electric field lines around tiny positively charged and negatively charged objects

Question 31

How can you see electric fields?

Answer 31

You can’t