Electrostatic Forces

Question 1

What is no.1 rule

Answer 1

FRICTION TRANSFERS ELECTRONS

Question 2

What is electric force governed by

Answer 2

Charge

Question 3

What is electrostatics measured in

Answer 3

Coulombs ( C )

Question 4

What two forms do electrostatics come in

Answer 4

Positive and Negative

Question 5

What are the two basic particles that carry charge

Answer 5

Protons- Positive +1.6x10^19

Electrons - Negative +1.6x10^19

Question 6

What happens if you move electrons to a common point

Answer 6

They create a static charge

Question 7

What is the only material you can create a static charge with without a power supply

Answer 7

An insulator

Question 8

Definition of an insulator (give examples)

Answer 8

Materials that do not allow currents to flow

eg. wood, rubber, plastic

Question 9

Definition of a conductor ( give example )

Answer 9

Materials that readily allow conduction of electrical current. eg. metals

Question 10

How do you build a static charge

Answer 10

Take 2 insulators and rub them together

Question 11

Why can’t you build a static charge with conductors

Answer 11

The charge will just spread out

Question 12

Name 4 uses of static electricity

Answer 12

Spray Painting
Photocopier
Defibrillation
Electrostatic precipitator

Question 13

How does spray painting work - spray can

Answer 13

1. As paint goes out of can, FRICTION TRANSFERS ELECRONS between paint and nozzle
2. Paint all has same charge, paint particles repels each other + spreads out

Question 14

How does spray painting work - bike frame

Answer 14

Paint has opposite charge to bike - attracts

- evenly paints bike

Question 15

How does a photocopier work ( 5 steps )

Answer 15

1. Charge barrel
2. Place document on screen, shine light
3. Where light hits barrel, charge resembled
4. Spray toner with opposite charge
5. Roll barrel

Question 16

Definition of defibrillator

Answer 16

A device used to attempt to restart a person heart

Question 17

How does a defibrillator work

Answer 17

By putting two static charges in contact wit body

One paddle is positive the other negative -together cause a current

Question 18

Definition of electrostatic precipitator

Answer 18

Used to remove carbon emissions from coal power stations

Question 19

How does an electrostatic precipitator work

Answer 19

1. Carbon filled smoke goes through high voltage grill
   ( +20,000 volts)
2. Smoke particles pick up positive charge (from grill)
3. Particles attracted to negatively charged plates
   4.Collecting plates are knocked to remove the now neutralised smoke particles, which then fall into a collector.

Question 20

Dangers of electrostatics

Answer 20

At a petrol pump, flowing petrol has FRICTION which TRANSFERS ELECTRONS to build a static charge which can cause a SPARK.

This can cause an explosion = not good

Question 21

How to solve dangers (petrol pump)

Answer 21

Make the pump out of metal- connected to earth- electrons will conduct to earth as charge transfers, so large charges cannot build.